The past few years have seen a plethora of bell pepper colors hitting the market. Purple being just one of them. There's also a brown one, a chocolate (supposedly different from the brown), a gold one, and, of course, the usual yellow, red, and orange.
Once you branch out from bells, it's incredible the number of colors. Red, yellow, orange, purple, pink, blue, black, striped in various colors. There even are white ones and at least one that is green when ripe.
All this without even thinking about hot chilies.
One of my favorites is an Hungarian heirloom called Sweet Apple. The skin is yellow, when unripe---instead of the more usual green---ripening to a flame orange, then scarlet. While growing it resembles a miniature yellow delicious apple.