Watercolors is XM’s “smooth jazz” channel. I occasionally listen to KKSF/103.7 in the car, but rarely for long — the commercials are far too disruptive.
On XM, of course, there aren’t any commercials — which makes Watercolors a much more listenable channel. Smooth Jazz still isn’t my preferred musical genre, but it does a dandy job of masking conversations in the office next door without distracting me too much, so I’m sure I’ll be back.