Yellow Whiz is supposed to be a one-coater, but like with most yellows, you'll need more than that to even out the color. The first coat of Yellow Whiz will be streaky, no matter if you use a thin or thick coat. The formula is a little runny, so the color can be a bit hard to control. I got pretty even coverage by applying two thin coats followed by a thicker one.
I love this color! It's so pretty and cheery.
For my pics, I applied three coats of Yellow Whiz over a coat of Seche, no top coat.