I don't believe any lip shade is off-limits, but texture is key. A sheer lipstick in a healthy pink or neutral color looks more polished and grown-up than a super-shiny gloss.
The most versatile lipstick you can own is a shade that's just a bit brighter than your natural lip color.
When I first got into making makeup, I didn't necessarily want to start a company. I just wanted to make a lipstick that looked like lips, only better.