Love my chickies!! :
To start, MFD's are not broody. Never seen any look twice at an egg, as a matter of fact, so plan on using a quality incubator, or two...
They are really pretty late to develop their color...at LEAST a year, more like 18 months.
"Incest" in chickens isn't really quite the same as other species. You can see problems, but several generations down the road. I think you'll be just fine, just introduce some new blood from time to time from quality stock, and you shouldn't have any problems.
Cull chicks with obvious problems from the get-go, but DON'T cull/rehome for color until they are at least a year old. And, I'm sure you've already thought of this, but keep your definite breeders segregated from the younger birds, until you can get an idea of how the color is developing.
And, good luck!!
thank you....all my MFD's are babies "4 days old". Should i just wait the 18 month's before i breed so i can pick the best feathered ones for the job?? Or will i have to make a good guess early only..." say 4 month's " if i want to start breeding early??