Hi Jean,
I was waiting for those who actualy breed wheatons to reply, but I see that they may have missed the post, so i will help if I can
We breed silvers, and the are supposed to have striping in their hackle and sadle, but I do find that with age that seems to fade, the younger cockerls are very stripie, by about 5-6 months old you have enough to determine if they will shoe well..but with chickens they shed about 5 times by 6 months old, then most shed their feathers annually, so in reality the never get their \"final\" feathers until they die.
I am prety certain the ideal wheaton has no striping, but also know others have mentiond that it is a hard feat to accomplish, so for breeding I would rcomnd using the ones with the least amount of striping at 5-6 months old. as they can fade with age, but if it is there, it will remain in the gene pool.