Color looks are in the Color FX room. Park your playhead on a clip. Go over to Color FX and drag one of the presets from the ColorFX bin into the node window.
From there, it's practice makes perfect to see how the nodes work and how to build up a tree. The manual explains the bare bones basics. Far better is the PeachPit book: Color Correction in Final Cut Studio (yep, here in the lafcpug store). If you're just getting into Color, you need it. Best $35 buck investment you can make.