I'm trying to change the color of the event list in only the mega menu seen below. But I have no idea how to do it. I've done some searching and seen recomendations for CSS but when I tried nothing worked when placed under block > advanced > Additional CSS or in customizer Additional CSS.

At the very least I'd like all the text to be white but really I might like to have diffenent colors for different sections. And adjust the size slightly too.

Thanks for any help or guidence.