So many responses! Thanks so much guys!
I ended up washing all the solid blacks together. I had about 3 yards total of it. I was going to use a solid black to make something else and decided to wash them all together.
I will wash the light greys and the whites I plan to use to make the quilt together. Just to make sure everything is washed.
I like the wash all or don't wash any rule. BUT I am mostly a scrap quilter so a lot doesn't end up getting washed! Is this bad??
Thanks again guys!