I painted my nails the other day using China Glaze's Rainbow, which is an iridescent white polish. I was really hoping for a full rainbow of colors in the shimmer, but it ended up looking mostly pink to me. It's translucent, but I didn't have the time or want to spend the effort to see what it looked like with several coats.
I tried an anti-yellowing top coat underneath because I already had it on. It obviously wasn't intended to be used as a base coat. 8 out of 10 nails are chipped today, and I painted them late the night before last. Not a good track record! But I did use it for something it wasn't intended to be used for... Mea culpa.