To get this coloring effect (PSP 8):
I started with this image:
Crop it to a square size. Do NOT resize to 100X100 pixels yet. Now we have this:
Duplicate the background once. De-saturate this layer (Shift+H). I set the saturation to about -70. Merge (Flatten) the layers (Layers-->Merge-->Merge All (Flatten)) We now have this:
We will now color her eyes. Create a new raster layer and set the blend mode to Overlay. Use the paint brush tool and color in the eyes by hand. For Alexis' eyes, I used #7DAFF9. This is the reason we haven't resized the picture yet, because we want to color the eyes when the picture is as detailed as possible. We now have this:
Now, on the Background layer, use the soften brush (in Photoshop I believe it's the smudge brush) to smooth her face. When I use the soften brush for this purpose I usally set the Hardness to about 50. We now have this:
Resize the image to 100X100 pixels (finally). While the background layer is selected, sharpen the image (Adjust-->Sharpness-->Sharpen). We have this:
Her face is kind of pixely due to the sharpening, so I went back over her skin with the soften brush one more time. You can certainly skip this step if you so choose.
Duplicate the background layer. Set the blend mode to overlay. This is what we have now:
Duplicate the background layer again. Set the blend mode to soft light. We have:
Finally, I merged (flatten) all of the layers and added a simple black border using a 1 pixel border brush. The final result is this:
I always save my icons as .png and not .gif; the image quality is much better.