I have 2 blue Orpington hens. They are a little more than a year old I think. Just recently I started noticing that their beautiful blue coloring seems to be "washing out" and turning what looks like tan. The grey feathers are looking light brownish and the dark grey on their head and neck seem to be lightening up into the same looking color. Their behavior is normal and they are eating and drinking normal. Is there something wrong with them?? Why would this be happening!