I've been trying my hand at quilt restoration. I'm working on a friend's grandmother's flower garden quilt. All of the yellow hexagons in the quilt are disintegrating. I read about this in a magazine article once - I think it's caused by a chemical in the dye.
So here is a before:
And an after - it's not the same block, but you get the idea.
It's not a perfect match, color-wise, but it works and after months of searching, it's as close as I could come. It actually looks a bit closer in person than it does in the photos.