As you may have understood this is not about lipstick. Its about Labia Minora or the "pussy lips" as in more common language.
I have noticed that some women has strong coloration to the Labia Minora, much in the same way as everybody have stronger coloration to the nipples. I think this is most common to Asians and Latin Americans.
As an example we have womens like Jade Hsu, Aneta Smrhova and Mindy Vega with this stronger than normal coloration. White womens often has very much the same coloration all over.
Who else besides these womens has a strong coloration to the Labida Minora?
Example pictures of the womens mentioned above: