Exercise in Contrast
This is an example of how contrast effects colors... many of you, looking at the 12 step color wheel thought that the last ( lowest ) color on the left side of the wheel was Purple or Violet and therefore thought that Purple or Violet was a cool color when in fact it is not. The last, lowest color on the left side of the wheel is actually a Dark Blue. The contrast of the Purple swatch to it's right causes the Blue to have a purple tint. Cover up the purple on the right and you'll see that the other color really is only a Blue.
In this example above, the H is the same color on both sides... its the contrast of the color surrounding each side that causes it to look the way it does.
I made this example using a Gradient ( light gray to dark gray ) on the bottom layer, and then used a second layer to type the H. Quite simple actually... but I could swear that the right side of that H is lighter ?????