Stay away at all costs:
I had a very bad time with Seattle Paint Supply.
The staff made a lot of mistakes (which cost me $$$) and was very rude and unapologetic about the whole thing.
I bought three gallons of white paint. Unfortunately, I discovered that they were mis-tinted after my painter had put them up. Went back for more cans, they were out so gave us two new cans and said the next would be ready tomorrow. Went back for the next and they had lost it. Went back the next day and got it. After putting it up, discovered that it too was mis-tinted. Called for a replacement and they were indignant about it. After haggling with them, they finally agreed to give me a new can if I brought in the old one.
All in all, they cost me probably $450 and several hours of driving, all without an apology. I tell everyone I know to stay away. Sherwin Williams has much better customer service.