Short and sweet:
Why is lips red?
Because lips are a “mucous membrane” body part which shows the red color of blood. I’m sure you can think of a couple of others.
I’m not red, I’m sort of pinkish beige.
Lips is often red 'cause they is often covers with lipsticks. Douglips, I don’t reckon you lips is covers with lipsticks at the particular moment, otherwise, you lips is red, too.