I apologize in advance if this has been mentioned b4 as I didn't have time to go through all the posts.
When you are debating like this, you may have heard the suggestions of using a door viewer (back you away from the quilt in effect) or maybe even a ruby red viewer* (show contrast, eliminating confusing color input). You can also use your camera or computer to help answer your questions or help you make a final decision. When you have the picture taken, zoom out. With your pics here on our forum on the Internet, you can probably just hold the Ctrl key down while you work the wheel on your mouse.
It's amazing what a little distance will do to help your...um, well, perspective! :-)
Happy designing!
*Note: If you have much red or even pink in your blocks, a Ruby Red viewer isn't as much of a help.