Today, the preponderance of Ouessant sheep are black, but they also occur in white and various shades of browns and grays. It is unclear whether the recent prevalence of these other colors is due to crossbreeding or different selection pressures. Many claim the original island sheep were black or dark brown. Others observe that early photos show many white sheep. The islanders supposedly selected black sheep for breeding because the women wanted to wear black clothing without having to dye the fibers.
The sheep we have in our flock are Quessant/Shetland crosses. Initially, when our sheep were 50:50 crosses they had colors that were strongly influenced by their Shetland mothers. We had sheep that were black, brown, and white, but we also had sheep with other color characteristics not found in the Ouessant breed. As the percentage Ouessant has increased the preponderance of black sheep has increased, and we still have brown and white sheep, too. But, very little of the Shetland characteristics remain.