All things being equal to a non-colored horse concerning conformation, temperament, soundness, and level of training? Maybe, but not a heck of a lot more. Color is just a bonus, and should always be the last consideration when looking at a horse.
I agree with SR. If I was looking at 2 horses that were both very similar in ability, temperament, training, confo, and bloodlines but one was buckskin and one was sorrel, I would pay a little more for the buckskin, simply because it would likely be priced a bit higher.
So tell me Piaffe and Paint Mom, was color the first consideration for you when looking for a horse? I hope not, because otherwise no wonder there are so many color breeders who don't care about conformation, soundness, or temperament. As long as they have people putting color before substance, they'll always have someone who will buy their train wrecks.
I'm not going to lie, I always check out the progeny from True Colours Farm.
The day is coming when I will be working full time again and will have more money to play with. If in my search I come across two horses that are equal in conformation, temperament and overall health but one is a chestnut and one is a buckskin, I'll probably go with the buckskin, just for something different. I'd pay extra too.
Ashamed to admit it but colour is flashy to me. Would never choose colour to the exclusion of all the important characteristics that I look for but hell, if presented with a choice and everything else was equal, yep, count me in.