okay about half way down, this at least says that roans can be born any color, but unlike grays, have dark heads... GRAY VS ROAN HORSES: How to tell the difference between gray and roan
"In horses, both true roan genes and grey genes are dominant genes. That is, a horse cannot hide these genes, if it has one [or both] of these genes, it will express and become evident. If it is roan, it has to have a roan parent, and if it is grey, it has to have a grey parent.
Frequently, AQHA registered Quarter Horse are listed as being roan, when they are not roan, but grey. That is because inexperienced breeders can mistake young grey horses for roans, report them as roans to AQHA, and it is recorded that way on their permanent papers.
Responsible roan horse breeders often consider any foal that appears roan born from both a roan and a grey parent, to be grey until proven otherwise (after 3-4 years of age). 50% of the time, they will turn grey. And in some cases - especially horses which are both roan + grey - this cannot be determined conclusively before they are 3 years old.
If you are interested in buying a roan horse, and do not want a grey, make sure neither of its parents are grey. (Remember, the AQHA registration certificate offers no conclusive proof of this, as it is only as reliable as the information reported.)
So, how can you tell a young grey horse from a young roan horse, especially if you do not know the color of its parents?
A grey horse will show greying (white hairs) on its face, in equal or higher density than on its body coat, usually fairly early on. It is progressive, and a grey horse gets whiter each year. Any color horse can inherit the grey gene, but every grey horse will have at least one grey parent.
A true roan horse will have a solid colored head and legs, the dark color legs usually make a stalagmite point up its legs above the knees & hocks, and its roaning (white hairs) will be dispersed over its body. The degree of roaning (amount of white hairs) will vary from horse to horse but will remain consistent over its lifetime to that horse. The roan over its body will vary seasonally, (lightest in spring, medium in summer, darkest in winter). A roan foal is often born looking solid colored.
If it is a light color horse, (carrying creme or dun gene) it may not display its roaning until older. The roan foal will show a lot of coat color development with each shedding, but look for slight roaning in its flanks when born, or creamy underpinning, or silver legs. After it sheds once or twice, you should know whether it is roan or not. It may be lighter as a yearling than as a 2 year old, but past that, roan is not a progressive color. When it reaches its permanent adult roan color, it will remain that way throughout its life. A roan horse will always have at least one roan parent."
from *Hancock Horses .com**|**ARTICLES**|**The equine roan gene
the paint didn't have any white hairs throughout his body when we got him, at 3yro, but now we keep finding more and more this year as he sheds out more.
for all i know my bay will have more next year like this paint. for all i know, one of her parent is a roan. i literally don't know her bloodlines save for the fact that she is a QH/arab
there are more websites, but for the life of me i can't find them