But in any case, make samples! If you can get small, I mean really small jars of paint, do it. Paint up a few scraps of wood....or maybe even cardboard, then lean them around the walls, etc, to get an idea of the color.
I liked the green I picked for the bathroom....until we got it on 2 of the walls. So I added everything I could find around here to lighten it, make it more yellow. I actually like that new green...but will never be able to re-create it. I then got a pint of yellow-with-a-dab-of-green....that's what is on the base of the footstool. If there is green in it, I haven't seen it yet!!!!
I have noticed others do this too.