Respectfully, you're too quick to dismiss saturation. Unless you have a color very close to either white or black, decreasing saturation makes the color more gray, and increasing saturation makes the hue more vibrant/noticeable.

In our example, balancing the saturation of the left colors makes a meaningful perceptual difference (again, I'm not saying anything about aesthetics).

Here is a side-by-side comparision with saturation values shown for each color. http://peoplesign.com/content/colorSaturationHN2.png