AFRMA

American Fancy Rat & Mouse Association

Fancy Rat Genes, Genetic Code Listing

For more rat genetics, see the AFRMA Rat Genetics book, specific articles listed with the various standards descriptions, and the articles on the Info Pages: Breeding – Colors/GeneticsRat Genetics, part 1, Rat Genetics, part 2, Rat Genetics, part 3. See also the Rat Biology article Where do Rat Coat Colors Come From?
See the AFRMA Rat Color Standards book and the Standards pages for photos.

See also Fancy Rat Genes, Alphabetical Name Listing sorted by the name of the rat color or
Fancy Rat Genes, Agouti-based Colors,
Fancy Rat Genes, Black-based Colors,
Fancy Rat Genes, Marked Rats, or
Fancy Rat Genes, Coats & Misc. for breakdowns.


Following are the rat genes sorted by genetic code with colors in each gene section that needs that gene to make that color.


Note: Rat genetics were not studied as much as the mice so a lot of the genetic codes have been given by fanciers or are not known

A  Am  B  Br  C  Cs  Cu1  Cu2  Cw  D  Dal  Dmbo  Fr  Fy  Fz  G  H  Hr  K  M  Me  N  Oe  P  Pe  R  Re  Rg  Rnu  Sa  Sh  Shn  Sl  St  Wv  ?

A: Agouti
A (agouti)AgoutiAA or Aa (i.e. A–)
Agouti: pink-eyedA– pp
(Silver Fawn)
Silver FawnA– pp
(P.E. Agouti; Argente in mice)
AmberA– pp (P.E. Agouti)
or A– mm pp (P.E. Cinnamon) (a.k.a. a light Silver Fawn)
Blue AgoutiA– gg*
(Opal)
OpalA– gg*
(Blue Agouti)
Agouti: Blue: pink-eyedA– gg pp*
(Apricot Agouti)
Apricot AgoutiA– gg pp*
(P.E. Blue Agouti)
Chocolate AgoutiA– bb
(dark Cinnamon; see also Hawthorn Rat Varieties: Chocolate Agouti)
Agouti: Chocolate: pink-eyedA– bb pp
(Silver Fawn/P.E. Chocolate Agouti)
Agouti: PlatinumA– bb gg*
CinnamonA– mm
(mink agouti)
Cinnamon: redA– bb mm
Cinnamon: darkA– bb
(Chocolate Agouti)
Cinnamon: ruby-eyedA– mm Rr
Cinnamon: pink-eyedA– mm pp
(light Silver Fawn)
Cinnamon: silveredA– mm
(come out of Cinnamon Pearl litters that lose their silvering as adults)
Cinnamon PearlA– mm Pepe
ApricotA– bb pp Rr? or A– mm pp Rr?
FawnA– rr or AA bb rr
(ruby-eyed Agouti; Topaz U.K.)
Topaz (U.K.)A– rr or AA bb rr
(Fawn, U.S.)
Russian Blue AgoutiA– dd
Russian CinnamonA– dd mm
Russian FawnA– dd rr
Russian Platinum AgoutiA– bb dd gg*
Silver Blue AgoutiA– dd gg* or A– dd gg mm?*
Lilac AgoutiA– bb mm Rr
ChinchillaA– Cscs Fyfy**? or A– cchcch? or ?
(formerly called Silver Agouti; see Breeding the Chinchilla)
Argente CremeA– Cscs Fyfy** pp? or A– cchcch pp?
(chinchillated Silver Fawn)
Squirrel (U.K.)A– Cscs Fyfy** gg*? or A– gg cchcch?
(chinchillated Blue Agouti)
Turpin (U.K.)A– Cscs FyFy** Hro++H? or Cscs Fyfy** Hro++H? or A– cchcch HroHro++?
(chinchillated Essex)
LynxA– Cscs Fyfy rr?, A– Cscs Fyfy mm rr?, A– Ccch?, A–mm rr?, A– rr?, A– rr cchcch or ?
(came out of Chinchilla breedings)
Cinnamon Pearl MerleA– mm Me– Pepe*
Agouti MartenA– cmcm#
Agouti BurmeseA– cech+
(similar to extreme dilute gene in mice)
Russian Blue Agouti BurmeseA– cech+ dd
(Russian Blue Agouti Burmese; similar to extreme dilute gene in mice)
Agouti Siamese SableA– csc# (B.E. version shown as Agouti Burmese)
Agouti Point SiameseA– chch
B. E. Agouti Point SiameseA– chci+
(similar to extreme dilute gene in mice)
Agouti Point HimalayanA– chc
B.E. Agouti Point HimalayanA– cici+
(similar to extreme dilute gene in mice)
Albinocc (albino; covers up the actual color/marking so can be either an agouti-based or black-based color; a.k.a. P.E. White)
White: pink-eyedcc (albino; covers up the actual color/marking so can be either an agouti-based or black-based color) Note: extremely diluted P.E. Self colors or a P.E. Marked with all markings bred off can look like a P.E. White
White: black-eyedhehe or any h
(marked selected for no spots; in either agouti-based or black-based color)
a (non-agouti/self)Blackaa
Silver Blackaa B–
(selected for silvering)
Beigeaa rr or aa bb rr
(ruby-eyed Black; Buff U.K.)
Buff (U.K.)aa rr or aa bb rr
(Beige U.S.)
Champagneaa B– pp
(P.E. Black)
Champagne: paleaa bb pp
(P.E. Chocolate)
Champagne: dark–eyedaa B– mm rr
Chocolateaa bb or aa bb Rr or aa BB Rr
Silver Chocolateaa bb
(selected for silvering)
Cocoaaa bb mm (Coffee in U.K.),
aa bb mm Rr, aa Bb mm Rr,
aa Bb mm Rr (Havana in U.K.)
Coffee U.K.aa bb mm
(See also Hawthorn Rat Varieties: Coffee)
Havana: U.K.aa Bb mm Rr
Lilac U.K.aa bb gg mm Rr*; see also Hawthorn Rat Varieties: Lilac
Russian Blueaa dd
Russian Doveaa dd mm, aa bb dd gg*, aa dd gg mm*, aa bb dd
Russian Dove: pink-eyedaa dd mm pp, aa bb dd gg pp*, aa dd gg mm pp*,
aa bb dd pp
Russian Dove Pearl New!aa dd mm Pepe, aa dd amam Pepe
Blue-Beigeaa dd rr
Russian Platinumaa bb dd gg*, aa dd gg mm*, aa bb dd, aa dd mm
Russian Silveraa dd gg pp*, aa bb dd gg pp*, aa bb dd gg mm pp*, aa dd pp
Silver Blueaa dd gg* or aa dd gg mm?*
Blueaa gg*
(selected for dark shade)
Sky Blueaa gg*
(medium shade)
Powder Blueaa gg*
(selected for light shade)
Silveraa gg pp*
(P.E. Blue)
Platinum: black-eyedaa bb gg*
Platinum: ruby-eyedaa gg mm*
Platinum: pink-eyedaa bb gg pp*
Doveaa gg mm*, aa bb gg*
Lilacaa mm or aa amam
(selected for lighter color)
See photos from 1978 of original U.S.A. Lilac male Hershey and here, owned by Karen Hauser. He was found in a pet shop in Riverside, CA.
Silver Lilacaa mm Pepe or aa amam Pepe
(selected for colored hair shafts and lighter color)
Minkaa mm
(selected for darker color)
Silver Minkaa mm Pepe
(selected for colored hair shafts and darker color)
Pearlaa mm Pepe
(selected for most of the hair shaft to be white; is a dominant lethal)
Mink/Lilac Merleaa mm Me– pepe* or
aa amam Me– pepe*
Silver Mink/Silver Lilac Merleaa mm Me– Pepe* or aa amam Me– pepe*
(selected for colored hair shafts)
Pearl Merleaa mm Me– Pepe*
(selected for most of the hair shaft to be white)
Martenaa cmcm#
Marten: Himiaa cmch#
(Marten with points)
Burmeseaa cech+
(similar to extreme dilute gene in mice)
Sable Burmeseaa cece+
(similar to extreme dilute in mice)
Russian Blue Burmeseaa cech+ dd
(similar to extreme dilute gene in mice)
Blue Burmeseaa cech+ gg
(similar to extreme dilute gene in mice)
Siamese Sable: AgoutiA– csc# (B.E. version shown as Agouti Burmese)
Siamese Sable: light/show versionaa csc#
Siamese Sable: mediumaa csch#
Siamese Sable: dark (shown as Sable)aa cscs#
Siamese: Seal Pointaa chch
Siamese: Black-eyed Seal Pointaa chci+
(similar to extreme dilute gene in mice)
Siamese: Blue Pointaa chch gg*
Siamese:
B. E. Blue Point
aa chci+ gg*
(similar to extreme dilute gene in mice)
Siamese: Chocolate Pointaa bb chch
Siamese: Russian Blue Pointaa chch dd
Siamese:
B. E. Russian Blue Point
aa chci+ dd*
(similar to extreme dilute gene in mice)
Himalayan: Blue Pointaa chc gg*
Himalayan: B.E. Blue Pointaa cici+ gg*
(similar to extreme dilute gene in mice)
Himalayan: Russian Blue Pointaa chc dd
Himalayan: B.E. Russian Blue Pointaa cici+ dd
(similar to extreme dilute gene in mice)
Himalayan: Seal Pointaa chc
Himalayan: Black-eyed Seal Pointaa cici+
(similar to extreme dilute gene in mice)
Albinocc (albino; covers up the actual color/marking so can be either an agouti-based or black-based color; a.k.a. P.E. White)
White: pink-eyedcc (albino; covers up the actual color/marking so can be either an agouti-based or black-based color) Note: extremely diluted P.E. Self colors or a P.E. Marked with all markings bred off can look like a P.E. White
White: black-eyedhehe or any h
(marked selected for no spots; in either agouti-based or black-based color)
Am/mo: American mink/mock mink (code by fanciers)
am (American mink)Lilacaa mm or aa amam
(selected for lighter color)
See photos from 1978 of original U.S.A. Lilac male Hershey and here, owned by Karen Hauser. He was found in a pet shop in Riverside, CA.
Russian Dove Pearl New!aa dd mm Pepe, aa dd amam Pepe
Silver Lilacaa mm Pepe or aa amam Pepe
(selected for colored hair shafts and lighter color)
Mink/Lilac Merleaa mm Me– pepe* or
aa amam Me– pepe*
Silver Mink/Silver Lilac Merleaa mm Me– Pepe* or aa amam Me– pepe*
(selected for colored hair shafts)
mo (mock mink)Aussie Minkaa momo
(see page 7 of the article)
B: Brown
b (brown)Chocolateaa bb or aa bb Rr or aa BB Rr
Silver Chocolateaa bb
(selected for silvering)
Beigeaa rr or aa bb rr
(ruby-eyed Black; Buff U.K.)
Buff (U.K.)aa rr or aa bb rr
(Beige U.S.)
Champagne: paleaa bb pp
(P.E. Chocolate)
Doveaa gg mm*, aa bb gg*
Cocoaaa bb mm (Coffee in U.K.),
aa bb mm Rr, aa Bb mm Rr,
aa Bb mm Rr (Havana in U.K.)
Coffee U.K.aa bb mm
(See also Hawthorn Rat Varieties: Coffee)
Lilac U.K.aa bb gg mm Rr*; see also Hawthorn Rat Varieties: Lilac
Chocolate Point Siameseaa bb chch
Russian Doveaa dd mm, aa bb dd gg*, aa dd gg mm*, aa bb dd
Russian Dove: pink-eyedaa dd mm pp, aa bb dd gg pp*, aa dd gg mm pp*,
aa bb dd pp
Russian Platinumaa bb dd gg*, aa dd gg mm*, aa bb dd, aa dd mm
Russian Silveraa dd gg pp*, aa bb dd gg pp*, aa bb dd gg mm pp*, aa dd pp
Platinum: black-eyedaa bb gg*
Platinum: pink-eyedaa bb gg pp*
Chocolate AgoutiA– bb
(dark Cinnamon)
Platinum AgoutiA– bb gg*
ApricotA– bb pp Rr? or A– mm pp Rr?
FawnA– rr or AA bb rr
(ruby-eyed Agouti; Topaz U.K.)
Topaz (U.K.)A– rr or AA bb rr
(Fawn, U.S.)
Silver Fawn: P.E. Chocolate AgoutiA– bb pp
Cinnamon: redA– bb mm
Cinnamon: darkA– bb
(Chocolate Agouti)
Lilac AgoutiA– bb mm Rr
Russian Platinum AgoutiA– bb dd gg*
Br: Bristle Coat (code by AFRMA)
Br (bristle coat)Bristle CoatBr
(code given by AFRMA)
C: Color/Chromogen/albino Series
cmMartenaa cmcm#
Marten: AgoutiA– cmcm#
Marten: Himiaa cmch#
(Marten with points)
ce (extreme dilute, code by Nichole Royer)Burmeseaa cech+
(similar to extreme dilute gene in mice)
Burmese: Sableaa cece+
(similar to extreme dilute in mice)
Burmese: Russian Blueaa cech+ dd
(similar to extreme dilute gene in mice)
Burmese: Blueaa cech+ gg
(similar to extreme dilute gene in mice)
Burmese: AgoutiA– cech+
(similar to extreme dilute gene in mice)
Burmese: Russian Blue AgoutiA– cech+ dd
(similar to extreme dilute gene in mice)
csSiamese Sable: AgoutiA– csc# (B.E. version shown as Agouti Burmese)
Siamese Sable: light/show versionaa csc#
Siamese Sable: mediumaa csch#
Siamese Sable: dark (shown as Sable)aa cscs#
ch (Acromelanism/Himalayan)Burmeseaa cech+
(similar to extreme dilute gene in mice)
Burmese: Russian Blueaa cech+ dd
(similar to extreme dilute gene in mice)
Burmese: Blueaa cech+ gg
(similar to extreme dilute gene in mice)
Siamese: Seal Pointaa chch
Siamese: Black-eyed Seal Pointaa chci+
(similar to extreme dilute gene in mice)
Siamese: Chocolate Pointaa bb chch
Siamese: Russian Blue Pointaa chch dd
Siamese:
B. E. Russian Blue Point
aa chci+ dd*
(similar to extreme dilute gene in mice)
Siamese: Blue Pointaa chch gg*
Siamese:
B. E. Blue Point
aa chci+ gg*
(similar to extreme dilute gene in mice)
Himalayan: Seal Pointaa chc
Himalayan: Russian Blue Pointaa chc dd
Himalayan: Blue Pointaa chc gg*
Burmese: AgoutiA– cech+
(similar to extreme dilute gene in mice)
Burmese: Russian Blue AgoutiA– cech+ dd
(similar to extreme dilute gene in mice)
Siamese: Agouti PointA– chch
Siamese:
B. E. Agouti Point
A– chci+
(similar to extreme dilute gene in mice)
Himalayan: Agouti PointA– chc
ci (intense dilute; code by Nichole Royer)Siamese:
Black-eyed Seal Point
aa chci+
(similar to extreme dilute gene in mice)
Siamese:
B. E. Russian Blue Point
aa chci+ dd*
(similar to extreme dilute gene in mice)
Siamese:
B. E. Blue Point
aa chci+ gg*
(similar to extreme dilute gene in mice)
Himalayan: Black-eyed Seal Pointaa cici+
(similar to extreme dilute gene in mice)
Himalayan: B.E. Russian Blue Pointaa cici+ dd
(similar to extreme dilute gene in mice)
Himalayan: B.E. Blue Pointaa cici+ gg*
(similar to extreme dilute gene in mice)
Siamese:
B. E. Agouti Point
A– chci+
(similar to extreme dilute gene in mice)
Himalayan: B.E. Agouti PointA– cici+
(similar to extreme dilute gene in mice)
Ivory/B.E. Creamcic+
(similar to extreme dilute gene in mice)
c (albino)Albinocc (albino; covers up the actual color/marking so can be either an agouti-based or black-based color; a.k.a. P.E. White)
Cs: Chinchilla spotting (code by Ann Storey)
Cs (chinchilla spotting)ChinchillaA– Cscs Fyfy**? or A– cchcch? or ?
(formerly called Silver Agouti)
Argente CremeA– Cscs Fyfy** pp? or A– cchcch pp?
(chinchillated Silver Fawn)
LynxA– Cscs Fyfy rr?, A– Cscs Fyfy mm rr?, or ? (came out of Chinchilla breedings)
Squirrel (U.K.)A– Cscs Fyfy** gg*? or A– gg cchcch?
(chinchillated Blue Agouti)
Turpin (U.K.)A– Cscs FyFy** Hro++H? or Cscs Fyfy** Hro++H? or A– cchcch HroHro++?
(chinchillated Essex)
Cu1: Curly 1
Cu1 (curly1)Curly 1Cu1
Cu2: Curly 2
Cu2 (curly2)Curly 2Cu2
Cw: Cowlick
cw (cowlick)Cowlickcw
D: Dilute
d (dilute)Russian Blueaa dd
Blue-Beigeaa dd rr
Silver Blueaa dd gg* or aa dd gg mm?*
Russian Doveaa dd mm, aa bb dd gg*, aa dd gg mm*, aa bb dd
Russian Dove: pink-eyedaa dd mm pp, aa bb dd gg pp*, aa dd gg mm pp*,
aa bb dd pp
Russian Dove Pearl New!aa dd mm Pepe, aa dd amam Pepe
Russian Platinumaa bb dd gg*, aa dd gg mm*, aa bb dd, aa dd mm
Russian Silveraa dd gg pp*, aa bb dd gg pp*, aa bb dd gg mm pp*, aa dd pp
Russian Blue Burmeseaa cech+ dd
(similar to extreme dilute gene in mice)
Russian Blue Point Himalayanaa chc dd
B.E. Russian Blue Point Himalayanaa cici+ dd
(similar to extreme dilute gene in mice)
Russian Blue Point Siameseaa chch dd
B. E. Russian Blue Point Siameseaa chci+ dd*
(similar to extreme dilute gene in mice)
Russian Blue AgoutiA– dd
Russian CinnamonA– dd mm
Russian FawnA– dd rr
Russian Platinum AgoutiA– bb dd gg*
Silver Blue AgoutiA– dd gg* or A– dd gg mm?*
Russian Blue Agouti BurmeseA– cech+ dd
(similar to extreme dilute gene in mice)
Dal: Dalmatian (code by Nichole Royer)
Dal (Dalmatian; code by Nichole Royer)DalmatianDaldal*
Collared? (usually from Dalmatian breedings) or Heh? or Hehi?
Dmbo: Dumbo
dmbo (dumbo)Dumbodmbodmbo (ear gene)
Fr: Frizzy
frCR (Charles River hairless)Hairless: CR (Charles River)frCR
frHFuzzyfzfz or frH
Fy: Fading yellow
Fy (fading yellow)ChinchillaCscs Fyfy**? or A– cchcch? or ?
(formerly called Silver Agouti)
Argente CremeA– Cscs Fyfy** pp? or A– cchcch pp?
(chinchillated Silver Fawn)
LynxA– Cscs Fyfy rr?, A– Cscs Fyfy mm rr?, or ? (came out of Chinchilla breedings)
Squirrel (U.K.)A– Cscs Fyfy** gg*? or A– gg cchcch?
(chinchillated Blue Agouti)
Turpin (U.K.)A– Cscs FyFy** Hro++H? or Cscs Fyfy** Hro++H? or A– cchcch HroHro++?
(chinchillated Essex)
Fz: Fuzzy
fz (fuzzy)Hairlesshrhr or fzfz
Fuzzyfzfz or frH
G: Gray (code by Nichole Royer)
g (gray; code by Nichole Royer)Blueaa gg*
(selected for dark shade)
Sky Blueaa gg*
(medium shade)
Powder Blueaa gg*
(selected for light shade)
Silveraa gg pp*
(P.E. Blue)
Doveaa gg mm*, aa bb gg*
Lilac U.K.aa bb gg mm Rr*; see also Hawthorn Rat Varieties: Lilac
Platinum: black-eyedaa bb gg*
Platinum: ruby-eyedaa gg mm*
Platinum: pink-eyedaa bb gg pp*
Russian Doveaa dd mm, aa bb dd gg*, aa dd gg mm*, aa bb dd
Pink-eyed Russian Doveaa dd mm pp, aa bb dd gg pp*, aa dd gg mm pp*,
aa bb dd pp
Silver Blueaa dd gg* or aa dd gg mm?*
Blue Burmeseaa cech+ gg
(similar to extreme dilute gene in mice)
Blue Point Siameseaa chch gg*
B. E. Blue Point Siameseaa chci+ gg*
(similar to extreme dilute gene in mice)
Blue Point Himalayanaa chc gg*
B.E. Blue Point Himalayanaa cici+ gg*
(similar to extreme dilute gene in mice)
Platinum AgoutiA– bb gg*
Blue AgoutiA– gg*
(Opal)
OpalA– gg*
(Blue Agouti)
Pink-eyed Blue AgoutiA– gg pp*
(Apricot Agouti)
Apricot AgoutiA– gg pp*
(P.E. Blue Agouti)
Silver Blue AgoutiA– dd gg* or A– dd gg mm?*
Russian Platinum AgoutiA– bb dd gg*
Squirrel (U.K.)A– Cscs Fyfy** gg*? or A– gg cchcch?
(chinchillated Blue Agouti)
H: Hooded
Hre (restricted)Capped-Stripehreh; Hrehre (lethal)?
BerkshireHh or hhe or hihi or hihn
Hro (Robert/Essex; code by Sheila Sowter)EssexHro++ or Hro++H (color fading gene; has Berkshire markings but breeds as a Self)
BaldieHro++h?
Turpin (U.K.)A– Cscs FyFy** Hro++H? or Cscs Fyfy** Hro++H? or A– cchcch HroHro++?
(chinchillated Essex)
hi (Irish)English IrishHh, or Hhi if no Hooded produced in 2 Irish breedings
IrishHh, or Hhi if no Hooded produced in 2 Irish breedings
BerkshireHh or hhe or hihi or hihn
Collared? (usually from Dalmatian breedings) or Heh? or Hehi?
Barebackhh or hhe or hHms or hhi?
hn (notch)Cappedhnhn
BerkshireHh or hhe or hihi or hihn
he (extreme)Maskedhehe
BerkshireHh or hhe or hihi or hihn
Collared? (usually from Dalmatian breedings) or Heh? or Hehi?
Barebackhh or hhe or hHms or hhi?
Tri-Merleheh Me?
White: black-eyedhehe or any h
(marked selected for no spots; in either agouti-based or black-based color)
h (hooded)Hoodedhh or hml
(Hm=Hooded Modifier; hms or hml—short or long)
English IrishHh, or Hhi if no Hooded produced in 2 Irish breedings
IrishHh, or Hhi if no Hooded produced in 2 Irish breedings
BerkshireHh or hhe or hihi or hihn
Barebackhh or hhe or hHms or hhi?
Tri-Merleheh Me?
Banded? (from Hooded stock)
hdu (down under)Down Underhdu? (dominant)
White: black-eyedhehe or any h
(marked selected for no spots; in either agouti-based or black-based color)
White: pink-eyedcc (albino; covers up the actual color/marking so can be either an agouti-based or black-based color) Note: extremely diluted P.E. Self colors or a P.E. Marked with all markings bred off can look like a P.E. White
Hr: Hairless
hr (hairless)Hairlesshrhr or fzfz
K: Kinky
k (kinky)Kinkykk
M: Mink
m (mink)Minkaa mm
(selected for darker color)
Silver Minkaa mm Pepe
(selected for colored hair shafts and darker color)
Lilacaa mm or aa amam
(selected for lighter color)
See photos from 1978 of original U.S.A. Lilac male Hershey and here, owned by Karen Hauser. He was found in a pet shop in Riverside, CA.
Silver Lilacaa mm Pepe or aa amam Pepe
(selected for colored hair shafts and lighter color)
Doveaa gg mm*, aa bb gg*
Cocoaaa bb mm (Coffee in U.K.),
aa bb mm Rr, aa Bb mm Rr,
aa Bb mm Rr (Havana in U.K.)
Coffee U.K.aa bb mm
(See also Hawthorn Rat Varieties: Coffee)
Havana: U.K.aa Bb mm Rr
Lilac U.K.aa bb gg mm Rr*; see also Hawthorn Rat Varieties: Lilac
Platinum: ruby-eyedaa gg mm*
Champagne: dark–eyedaa B– mm rr
Russian Doveaa dd mm, aa bb dd gg*, aa dd gg mm*, aa bb dd
Russian Dove: pink-eyedaa dd mm pp, aa bb dd gg pp*, aa dd gg mm pp*,
aa bb dd pp
Russian Dove Pearl New!aa dd mm Pepe, aa dd amam Pepe
Silver Blueaa dd gg* or aa dd gg mm?*
Pearlaa mm Pepe
(selected for most of the hair shaft to be white; is a dominant lethal)
Mink/Lilac Merleaa mm Me– pepe* or
aa amam Me– pepe*
Silver Mink/Silver Lilac Merleaa mm Me– Pepe* or
aa amam Me– pepe*
(selected for colored hair shafts)
Pearl Merleaa mm Me– Pepe*
(selected for most of the hair shaft to be white)
ApricotA– bb pp Rr? or A– mm pp Rr?
Silver Fawn: lightA– mm pp
(P.E. Cinnamon)
CinnamonA– mm (mink agouti)
Cinnamon: redA– bb mm
Cinnamon: ruby-eyedA– mm Rr
Cinnamon: silveredA– mm
Cinnamon PearlA– mm Pepe
Lilac AgoutiA– bb mm Rr
LynxA– Cscs Fyfy rr?, A– Cscs Fyfy mm rr?, or ? (came out of Chinchilla breedings)
Russian CinnamonA– dd mm
Silver Blue AgoutiA– dd gg* or A– dd gg mm?*
Cinnamon Pearl MerleA– mm Me– Pepe*
Me: Merle (code by Nichole Royer)
Me (merle)Merle: Cinnamon PearlA– mm Me– Pepe*
Merle: Mink/Lilacaa mm Me– pepe* or
aa amam Me– pepe*
Merle: Silver Mink/Silver Lilacaa mm Me– Pepe* or
aa amam Me– pepe*
(selected for colored hair shafts)
Merle: Pearlaa mm Me– Pepe*
(selected for most of the hair shaft to be white)
Tri-Merleheh Me?
N: Naked
n (naked)Nakednn
Oe: Odd-eye
oe (odd-eye)Odd-Eyeoe or ? (has 2 different colored eyes; usually pink/black but can be ruby/black or pink/ruby)
P: Pink-eyed Dilution
p (pink-eye)Champagneaa B– pp
(P.E. Black)
Champagne: paleaa bb pp
(P.E. Chocolate)
Pink-eyed Platinumaa bb gg pp*
Silveraa gg pp*
(P.E. Blue)
Pink-eyed Russian Doveaa dd mm pp, aa bb dd gg pp*, aa dd gg mm pp*,
aa bb dd pp
Pink-eyed AgoutiA– pp
(Silver Fawn)
Silver FawnA– pp
(P.E. Agouti)
AmberA– pp
(P.E. Agouti; a.k.a. a light Silver Fawn)
Silver Fawn: lightA– mm pp
(P.E. Cinnamon)
Silver Fawn: P.E. Chocolate AgoutiA– bb pp
ApricotA– bb pp Rr? or A– mm pp Rr?
Apricot AgoutiA– gg pp*
(P.E. Blue Agouti)
Pink-eyed Blue AgoutiA– gg pp*
(Apricot Agouti)
Argente CremeA– Cscs Fyfy** pp? or A– cchcch pp?
(chinchillated Silver Fawn)
Pink-eyed Whitecc (albino; covers up the actual color/marking so can be either an agouti-based or black-based color) Note: extremely diluted P.E. Self colors or a P.E. Marked with all markings bred off can look like a P.E. White
Pe: Pearl
Pe (pearl)Pearlaa mm Pepe
(selected for most of the hair shaft to be white; is a dominant lethal)
Russian Dove Pearl New!aa dd mm Pepe, aa dd amam Pepe
Silver Lilacaa mm Pepe or aa amam Pepe
(selected for colored hair shafts and lighter color)
Silver Minkaa mm Pepe
(selected for colored hair shafts and darker color)
Silver Mink/Silver Lilac Merleaa mm Me– Pepe* or
aa amam Me– pepe*
(selected for colored hair shafts)
Pearl Merleaa mm Me– Pepe*
(selected for most of the hair shaft to be white)
Cinnamon PearlA– mm Pepe
Cinnamon Pearl MerleA– mm Me– Pepe*
R: Ruby-eye/Red-eye
r (ruby-eye/red-eye)FawnA– rr or AA bb rr
(ruby-eyed Agouti; Topaz U.K.)
Topaz (U.K.)A– rr or AA bb rr
(Fawn, U.S.)
ApricotA– bb pp Rr? or A– mm pp Rr?
Russian FawnA– dd rr
Cinnamon: ruby-eyedA– mm Rr
Lilac AgoutiA– bb mm Rr
LynxA– Cscs Fyfy rr?, A– Cscs Fyfy mm rr?, or ? (came out of Chinchilla breedings)
Beigeaa rr or aa bb rr
(ruby-eyed Black; Buff U.K.)
Buff (U.K.)aa rr or aa bb rr
(Beige U.S.)
Champagne: dark–eyedaa B– mm rr
Chocolateaa bb or aa bb Rr or aa BB Rr
Cocoaaa bb mm (Coffee in U.K.),
aa bb mm Rr, aa Bb mm Rr,
aa Bb mm Rr (Havana in U.K.)
Lilac U.K.aa bb gg mm Rr*; see also Hawthorn Rat Varieties: Lilac
Havana: U.K.aa Bb mm Rr
Blue-Beigeaa dd rr
Re: Rex
Re (rex)RexRere
Rg: Ragged
rg (ragged)Raggedrgrg
Rnu: Rowett nude
rnu (rowett nude)Nudernurnu (Rowett nude)
Sa: Satin
sa (satin)Satinsasa
Sh: Shaggy
Sh (shaggy)ShaggySh
Shn: Shorn
shn (shorn)Shornshnshn
Sl: Spotting Lethal New!
sl (spotting lethal)B.E. Whiteslsl (recessive)
these suffer from aganglionic megacolon associated with white coat color, usually BEW but occasionally have small spot on head and hips and die usually within first week to 35 days after birth
St: Stub
st (stub)Taillessstst? (recessive)
Wv: Wavy
wv (wavy)Wavywvwv
?: Unknown genetics
?Banded? (from Hooded stock)
Blazemany possible
Coffee U.S.? (coffee with cream/gray-brown color)
Harley? (recessive; sparse, fine, wispy coat with no undercoat)
Roan (Husky)? (recessive; roan gene lightens color with each moult till rat is nearly white; always in Berkshire or Berkshire Blaze markings)
Roan: Striped? (recessive; a.k.a. Banded Husky)
Snowflake? (small white spots belly and sides; a.k.a. stippeltjes in the Netherlands which means dots)
Variegated? (2 Var. never produce Self or Hooded)
Velvet? (recessive; short plush coat similar to Rex rabbits)

C: Albino Locus (Burmese)+ (codes by Nichole Royer)
CFull color (no dilution)
ce+Extreme dilute
chAcromelanism (Himalayan/Siamese)
ci+Intense dilute
cAlbino (Pink-Eyed White)

C: Albino Locus (Marten and Siamese Sable)# (codes by Nicole Housel)
CFull color (no dilution)
cm#Marten
cs#Siamese Sable
chAcromelanism (Himalayan/Siamese)
cAlbino (Pink-Eyed White)

Note: Many rat colors/varieties have not been studied by geneticists so codes are given by fancy rat genetics experts or are unknown

Note: Capital letter=dominant genes unless otherwise noted; lower case letter=recessive genes

“–” means that either the dominant or recessive allele could occupy that space without affecting the outcome

* = g or Me or Dal code by Nichole Royer

** = Cscs Fyfy code by Ann Storey, N.F.R.S.

+ = ce or ci code by Nichole Royer

++ = Hro code by Sheila Sowter, N.F.R.S.

# = cm or cs code by Nicole Housel

? = genetics unknown

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Updated October 9, 2022