That's a non standard color... not conforming to any standard of perfection color variety that I'm familiar with. Typical of crossing colors.
I would call it white with leakage.
White can hide a lot of things underneath. My guess also as to where your colorful chicks are coming from is your white hens (from another post). Also, the color often described as grey is actually Blue. I thought some of my Silkies were black because they were so dark I didn't realize they were blue until a black chick hatched.