Chestnut horses aren't crazy, they're just curious.

For years, chestnuts horses were considered to be more hot headed and couldn't be easily controlled compared to other coloured horses.

But research from the University of Sydney has discovered there are no real behavioural differences between them.

A pilot study looked at more than 450 horses and found differences in behaviour weren't conducive to colour, but more likely to be attributed to age, breed and gender.

"No evidence was found to support that chestnut horses are more likely than bay horses to display behaviours often associated with training difficulties," the study said.

In fact, the only difference the study uncovered with chestnut horses was they were a little bit more curious.

They were more willing to go up to unfamiliar objects and were more bold in their decisions.

The researchers say this could explain why those in the industry have reservations about chestnuts.

"Chestnut horses may seem crazy simply because they get themselves into situations that tend to be more frightening or dangerous," they said.

Having looked after some of the best chestnut horses in Australia including Sebring and Star Witness, Widden Stud manager David Merrick says he hasn't noticed any differences.

"None of those (Sebring, Star Witness) are more aggressive, or temperamental than bays or browns," he told AAP.

"I've probably had more issues with bays than I've had with chestnuts."

Around one third of Widden Stud's stables are made up of chestnuts.

At the Inglis Easter Yearling Sale, brown or bay horses dominated the listings.

Only 12 per cent were chestnut, while less than three per cent were grey.