Definitely natural. First of all, kissing your lips is more fun than kissing your lipstick. That stuff feels gross. Also, if you were to kiss me on the cheek with red lipstick, I don't want to have to wash that crap off my face.
Second, red lipstick usually does not look good, at least to me. Red lipstick almost never looks better than natural, and it often makes you either look like a clown or a hooker (hence, the term "hooker red"). While you will definitely stand out, it's probably not the attention you want unless you're going to juggle for everyone looking at you.
As seems to be the trend here, I'm going to say go natural.
It depends on the girl. Some girls know how to apply makeup on themselves and look really hot with it. Those girls probably look hot without it. Some girls look alright wearing lipstick and other makeup. For some girls wearing makeup doesn't really help. It all depends on the girl.
yh id rather go natural, maybe if they were really chapped id say use soemthing to take care of that but as far as color I would say natural is ussually better, and plus make up is typically only used to cover up something you don't like about yourself so I say just be true yourself
if red means lipstick and nude means natural then I would say natural. I soemtimes like light pink lip gloss but for the most part I would say I would preffer a girls natural lip color, as well as nails most the time.