A couple of bits of advice we got when dithering about paint colors: get the samples, and hold them up during different times of day and/or in different weather. Sometimes, stuff that looks ok in low light looks dreadful in the sun, and vicey-versey. Oh, and when you have it narrowed down to a couple shades, it's fine to have the paint guys bring samples and paint little bits and take a look and compare - tends to look a bit different when it's actually up on your house vs. in a paint sample book.