I kinda think that your house should flow. That doesn't mean that every room has to be the same colour, but I think it's important that every room relates to the others in some way. I went to a friend of a friend's house once for dinner, and the first time I was there really struck a colour nerve. It's not that their particular choices weren't good ones (each to their own, right?), but the combination really left me feeling unsettled. Royal purple in the dining room, lemon yellow in the kitchen, tomato red in the living room, aquamarine in the office area. There's nothing wrong with those colours on their own, but when they were in rooms that were adjoining each other where at different points you could see both the kitchen and dining room or the dining room and living room or the dining room and the office or all four at once, just didn't work. That's why it's nice to have a palette to work from. Different colours that are in the same tonal family or have the same base colour (like the difference between a blue white and a yellow white) will always work together. And that's something you really have to consider when choosing paint colours.
Anyway, after feeling so inspired by that website, I thought it would be pretty easy to do yourself with any picture you find that you like. Here are a few I threw together really quick (aka they're not 100% perfect cuz I don't feel like spending an hour on it right now):
Any of the brighter colours (like the orange and yellow above) I'd use as accent colours instead of actual wall colours. Then you can dot them throughout the house in the form of throw pillows, art, or vases of flowers even. Anyway, the idea is to give yourself a base. Something you can work from. I don't like the rooms in houses to be matchy, but they should at least work together harmoniously.
UPDATE #1: Thanks to Not Martha, there's a website where you can upload any photo and it'll find a colour palette for you. Genius!