Basically, we got our paint from Ace Hardware. They have these racks of "Paint Pots" that let you buy good sized samples to take home and try out. They have big and small, but the bigger brands have more vibrant colors. You can try them out on a big, say 2'x2' square and look at them in all sorts of lights. Once you like them, Ace will mix larger volumes. We didn't always find colors we liked, but the pots also lent themselves to combinations of colors (see below) that got the whole family trying combos.
The below pictures includes one of all the Paint Pots we used. If you click on the pictures, you'll see the name/room.
The kitchen yellow is "Glistening Gold."
The kitchen orange (the big wall) is "Casa de Oro."
The living room (with our TV) is "Galveston Dust."
The dining room (with the masks) is equal parts "Clay Pot" and "La Terra". Not sure who thought of this combination (probably Kaj).
The fireplace room (with the vaulted ceiling) is actually a mixture of two colors - equal parts "Dried Leaves" and "Granny Smith". This color was invented by Saahil. He thought it should be called "Dried Granny".