do bridesmaids all have to wear the same kind of makeup. what if one bridesmaid wore a red lipstick when the other wore a nude shade?

It is up the couple how they would like the bridesmaids to look. However, it is tradition that all the bridesmaids look as identical as possible! That's including makeup :)

It's not necessary for the principles (bride, groom, attendants, close family) to match, to be identical. but they harmonize, avoid colors that clash with those other principles. Will the lady in neutral hued lipstick be conspicuous? Will people seeing the wedding party, the photos be wondering "What is wrong with that one lady's lips, they are so pale?" 

If things are too different there may have to be compromise like no super bright or super dark colors, but no super pale or super nude colors either. "You can't look like you're not wearing lipstick." 

I think if that happened, the wedding would still go on as planned.

What if the bridesmaids were of all different hair colors, races, and nationalities?  Would it make sense they had to wear the same makeup?