How can I safely warm up my recently colored hair?

I had my hair colored by someone new yesterday and I don't like it. I usually have some warmth and depth to it, but this stylist used a different color and it's just kind of drab. Is there a product I can use to just warm it up a bit myself, that would be safe to use over the color I just had? Or should I call the guy and tell him I'm not happy with it (awkward). I did pay a lot......and it didn't cover the gray real well, either. What should I do? It's not awful, just not real pretty. :(