Many cichlids only color up seasonally for spawning, and even then only if a suitable mate is found. Otherwise they could become easy prey with all the bright coloration.
Take beanii as an e.g
below a normal color female

now a female in spawning does

and I'm sure you've seen the pics of Nosferatu labridens yellow, where in spawning dress they are as yellow as canaries, or as bright as the Malawan Labidochromis caeruleus. But their normal color is like the one below