We went through that agony recently and I feel your pain. Sherwin Wiliams has a great tool just got an overall sense of how colors related to one another on various elements of the house. Even if you are not using SW it might be good to try. In the end, we went through about 6 rounds of samples to find color combos we liked and the key was buying poster board and painting each color on almost the whole thing (would have done the whole whole thing if we weren't in an apartment with no space). You can carry poster board around with one once it's dry, check out the color in various lights, hold it up to brick samples, other color samples, roofing etc and get a feel. Look at it in bright light, dim light, we even took it to our site to see how it would look at various times of day. It will probably look at tad darker on the actual house but not too much.

This all might seem like overkill to some but we had to choose so many colors (roof, trim, shutters, siding, shakes, door, brick) and were very unsure until we did this. On the other end there were no surprises either, we are very happy.

To upload photos you need to have them on a web host like photobucket or flickr and then add the link to the photo in the post. You can 'embed' the photo in the post that way.

HTH