A "nice tan"
A suntan or tan was a darkening of one's skin pigmentation due to sun exposure.
In 2364, Mack, the news vendor in the Dixon Hill series of holographic novels, upon hearing that the wan "Carlos" was supposedly from South America, sarcastically said he had a "nice tan." (TNG: "The Big Goodbye")
In 2370, Quark greeted Fallit Kot warmly, saying he looked tanned. (DS9: "Melora")