Rihanna Lawsuit -- She's Hot, Because She's Not Too Dark

Rihanna is "hot" because she's "not too dark" ... and that's what a guy claims was said in the firm that manages the singer's finances.

A fired employee claims the firm -- Flynn Family Office (FFO) had a sexist culture and comments were allegedly hurled that were racist. The fired employee claims one of the company's partners would say things like an assistant "lost points in [his] eyes because she was too dark."

FFO -- which also reps Kelly Ripa, designer Tory Burch and Katie Holmes -- also allegedly tolerated discussions about sex tourism and the relative "hotness" of Asian women.

And the suit claims there was loose talk about women, including comments such as a worker having an "ass of steel."