In my case, color! With blonde hair, beigeish skin, and beige eyelashes, I need something to brighten up. I use only natural colors but a little lip color is needed and a little brightness on the cheeks (just a tad). And mascara is a must with no color in my eyelashes. TMI?? :)
Women with darker hair color have darker eyelashes so they actually have some color on their face.
Hmm. Never thought about this. Thanks for sharing your reason.