Why it works: Fluorescent colors are a tough sell. A few years ago we went through a phase where fluorescent colors in mostly-white spaces were a big thing, but they were really big, and now I think that reads a bit dated. But here, the blue walls sort of blend with the black trim, which makes a nice counterbalance to the door. The darker colors keep the yellow from being gimmicky and unserious. And it helps, as always, that the blue's a bit more subdued.
11 Delightfully Unusual Color Combinations (Plus the Reasons Why They Work)