Drab is a color that is kind of like brown or gray or green, but not really like any of them. It's a color that's kind of boring and doesn't really make you happy or excited when you see it. Imagine if you mixed a bunch of different colors together, but didn't add enough of any one color to make it stand out. That's what drab looks like. It's not a bad color, but it's not very interesting either. It's just kind of there. People might use it to describe a boring outfit or a dull room that doesn't have any bright colors to make it more exciting to look at.