That depends on how much you'd like to have.

[Ah, this old chestnut. It's like looking in a mirror. She'd been so nervous about the moonlacing, when she'd first arrived, that her hands had started to crystalize...]

You won't suffer any ill health effects as long as you're doing some manner of contact with another person, but you won't exactly be wealthy. If I may be blunt, the more intimate the act, the more Chroma you earn.