As explained by Gavin Fitzpatrick:
Dun is an extremely rare colour, appearing in approximately one in every 1500 to 2000 litters. It can range from a light blue fawn, through a rich red fawn, up to a deep rich chocolate colour, with the dominating factor being a pink to brown coloured nose leather. Many Dun coloured greyhounds in the past have been listed and recorded as being Dark Fawn, Red Fawn or Red. They should never be listed as a type of Fawn or Red as they are a colour apart. In addition, when fawn is crossed with another fawn or brindle, black or blue coloured pups cannot issue from such mating. However, when Dun is crossed with fawn or brindle, it is almost certain that black coloured pups will issue from the mating. Research indicates that all present day Dun coloured greyhounds will have a double cross of Rocket Jet.
Rocket Jet is an Australian dog, but dun can also be found in a number of English, Irish and Danish dogs. I'm not aware of any American bred greyhounds that are throwing dun pups.
Wonderful puppy example of white/dun:
This little guy is Eikica Lucky Lucas [Eikica Anthon Berg Finest x Eikica Beauty Belisha] - he's Danish.
Another example:
This is Glencrane [Premier County x Glencora] - he's Irish.
Enjoy!
