Eva's Rat Colour Genetics Page -
Agouti Varieties

1. Agouti
   Overall impression: An Agouti rat shall have a rich redbrown band colour that gives the impression of prominent red splashes and black ticking evenly dispersed over the body. There shall be an even demarcation between top colour and belly colour.
   White markings and/or white hairs anywhere on the body shall be considered as faults.
   Under colour: Shall be black.
   Band colour: Shall be as strong, deep and warm red as possible.
   Ticking: Has to be black as raven looks.
   Belly colour: Belly shall have as dark under colour as possible with a silvery grey band and no ticking.
   Feet: Colour of feet to look as top colour.
   Eye colour: Black.
   Other name/s: Wild colour.
   Genetics: (No mutated genes).
   Known since: Since the rat was discovered by man. Agouti is the wild form, the original colour from which all other colours springs. In standards 1902 in England.

2. Chocolate Agouti
   Overall impression: Shall be a warm redbrown colour with chocolate ticking evenly distributed over the body. There shall be an even demarcation between top colour and belly colour. White markings and/or white hairs anywhere on the body shall be considered as faults.
   Under colour: Shall be chocolate.
   Band colour: Shall be as red as possible and that gives the impression of prominent red splashes.
   Ticking: Shall be chocolate.
   Belly colour: The belly shall have a chocolate under colour with a light silvery grey band and no ticking.
   Feet: Colour of feet to look as top colour.
   Eye colour: Black.
   Other name/s: Cinnamon, brown agouti, Red Agouti, Chocolate Agouti, chocolate ticked agouti. The name Cinnamon was used between 1935 and 1976.
   Genetics: (bb).
   Known since: 1935.

3. Cinnamon
   Overall impression: Shall be a warm cinnamon brown colour with chocolate ticking everly distributed over the body. There shall be an even demarcation between top colour and belly colour.
   White markings and/or white hairs anywhere on the body shall be considered as faults.
   Under colour: Shall be greyish brown.
   Band colour: Shall be a golden orange.
   Ticking: Shall be chocolate brown.
   Belly colour: The belly shall have a geyish brown under colour with a light silvery grey band and no ticking.
   Feet: Colour of feet to look as top colour.
   Eye colour: Black.
   Other name/s: Fawn Agouti, Mink Agouti.
   Genetics: (mm).
   Development of colour: This colour acts just a slightly lighter version of a normal agouti.
   Known since: 1925. In standards 1935 as Fawn Agouti, renamed as Cinnamon 1976.

4. Ruby Eyed Cinnamon
   Overall impression: To be a cinnamon brown colour with chocolate ticking evenly distributed over the body. There shall be an even demarcation between top colour and belly colour. No white markings or white hairs.
   Undercolour: To be greyish brown.
   Band colour: To be a golden orange.
   Ticking: To be chocolate brown.
   Belly colour: Belly to have a greybrown undercolour with a light silvergrey band and no ticking.
   Feet: To conform with body colour.
   Eye colour: Dark ruby.
   Other name: In the USA: cinnamon.
   Genetics: (probably mmRr)
   Development of colour: This colour looks like fawn at least up until the age of 4weeks, then it starts developing into a colour that reminds more of the true lynx (aabbdd). As adult this colour looks very much like black eyed cinnamon, the main difference is the ruby eyes and a slightly more reddish orange impression of overall fur colour.
   Known since: In Sweden 1991 under the name "SRS-lynx".

5. Silver Fawn
   Overall impression: Shall be a rich orange colour with silvery guard hairs (Monotrich) evenly dispersed over the body. The belly to be white as chalk and the demarcation between belly and top colour to be straight, sharp and clear cut.
   Under colour: White.
   Band colour: Rich orange.
   Ticking: Silvery white.
   Belly colour: As white as possible. (White as chalk.)
   Feet: To conform with top colour.
   Eye colour: Pink.
   Other name/s: Fawn, Argente, Amber, Brandgul (TRV).
   Genetics: (pp or ppbb).
   Known since: 1910. In NFRS standards as Silver Fawn 1935.

6. Fawn
   Overall impression: Orangebrown rat with darker ticking, light belly colour. There shall be an even demarcation between top colour and belly colour. No white patches or hairs.
   Undercolour: Lilac.
   Band colour: To be a rich dark brownish orange fawn colour.
   Ticking: To be chocolate.
   Belly colour: To be a light greyish brown.
   Feet: To conform with body colour.
   Eye colour: Dark ruby, almost black.
   Other name/s: Topaz, Argente and Ruby Eyed Silver Fawn.
   Genetics: rr.
   Development of colour: Born with pink eyes. Eyes are almost black at 14 days of age when the rat baby opens its eyes.
   Known since: A very common american rat colour that the american rat breeders is said to have bred for around 30 years. Imported to Sweden in 1986.

7. Opal
   Overall impression: An Opal rat shall have a rich orange band colour and blue ticking evenly dispersed over the body. There shall be an even demarcation between top colour and belly colour.
   White markings and/or white hairs anywhere on the body shall be considered as faults.
   Under colour: Shall be blue.
   Band colour: Shall be as strong, deep and warm orange as possible.
   Ticking: Has to be clearly blue, not light.
   Belly colour: Belly shall have as dark under colour as possible with a silvery grey band and no ticking.
   Feet: Colour of feet to look as top colour.
   Eye colour: Black.
   Other name/s: German Blue Agouti.
   Genetics: (dd).
   Known since: Not in standards in any rat club, occasional individuals exist, showed up in Sweden for the first time in 1995.

8. Lynx
   Overall impression: A Lynx rat shall have a rich orange band colour and lilac ticking evenly dispersed over the body. There shall be an even demarcation between top colour and belly colour.
   White markings and/or white hairs anywhere on the body shall be considered as faults.
   Under colour: Shall be lilac.
   Band colour: Shall be as strong, deep and warm orange as possible.
   Ticking: Has to be clearly lilac, not light.
   Belly colour: Belly shall have as dark under colour as possible with a silvery grey band and no ticking.
   Feet: Colour of feet to look as top colour.
   Eye colour: Black.
   Other name: Lilac Agouti.
   Genetics: (bbdd).
   Known since: Not in standards in any rat club, occasional individuals exist, showed up in Sweden for the first time in 1996.

9. English Blue Agouti
   Overall impression: An English Blue Agouti rat shall have a light bluish colour with orange and silver, plus English BLue ticking evenly dispersed over the body. There shall be an even demarcation between top colour and belly colour.
   White markings and/or white hairs anywhere on the body shall be considered as faults.
   Under colour: Shall be English Blue.
   Band colour: Shall be as strong, deep and warm golden orange as possible.
   Ticking: Has to be English Blue.
   Belly colour: Belly shall have as dark English Blue coloured under colour as possible with a silvery grey band and no ticking.
   Feet: Colour of feet to look as top colour.
   Eye colour: Black.
   Other name: Selen Agouti.
   Genetics: (gg, g not scientifically described).
   Known since: 1996?.

10. Russian Blue Agouti
    Overall impression: An Russian Blue Agouti rat shall have a rich orange band colour and blue ticking evenly dispersed over the body. There shall be an even demarcation between top colour and belly colour.
    White markings and/or white hairs anywhere on the body shall be considered as faults.
    Under colour: Shall be blue.
    Band colour: Shall be as strong, deep and warm orange as possible.
    Ticking: Has to be clearly blue, not light.
    Belly colour: Belly shall have as dark under colour as possible with a silvery grey band and no ticking.
    Feet: Colour of feet to look as top colour.
    Eye colour: Black.
    Genetics: (rb rb).
    Known since: Not in standards in any rat club, occasional individuals exist, showed up in Sweden for the first time in 2000.

In the Agouti rat most of the hairs are banded. Each of the secondary guard hairs have three bands of colour. The three bands are

1. the part of the hair that is most close to the skin (called base colour),
2. the tip of the hair (called tip colour), and
3. the part of the hair that is between these two, near the tip, (called the band colour).

In a colourbred rat the tip colour and the basecolour are truly supposed to be the same. Between the tip and the base of the hair there is a band of another colour - the second colour. Rats have some hairs that are longer than the rest (the Monotrich, also called primary guard hairs), and these are usually the same colour as the tip colour. In a colourbred rat the tip colour, the basecolour and the colour of the Monotrich are the same. The "under colour" is another name for the basecolour.

The agouti varieties of the rat have a lighter belly colour that can vary from greyish to white.

The effects mentioned above are caused directly by the agouti gene.

Last update: 13th of February 2003.
Copyright Eva Johansson.