I have had this crate for a couple years and haven't done a thing with it. It was painted black when I bought it. Which by the way, got at Goodwill for $2.
One day I grabbed a paint brush and some old yellow paint. Old, as in, had to scrape 2" of hardened paint off the top to get to the wet stuff underneath. The lid was obviously not on tight for the last couple years.
I dry brushed it. I am not sure if that is a real term or not but basically, I put a little bit of paint on the brush and I spread it on the crate as much as possible. If that makes any sense?
Here are pictures. Its a rough look, not fully painted. dry brushed.