I don't get it, how will affect customer service if a flight attendant is wearing red lipstick? It makes no sense, it seems to be just an excuse of a country that is turning more and more Islamic.
Turkish Airlines (Hover)
I agree that it doesn't seem logical that banning a specific color of two applications of make up will improve communications for the reasons stated. If they wanted to get flight attendants to look more natural, then banning all colored make-up would be more appropriate. However, I suspect that the secular Turks are on the right track and this ban is motivated by something else. That being said, an airline can enforce a reasonable grooming policy and banning a certain color of make up seems reasonable to me.