Frequently, when creating a GIF animation, you'll want a particular part of the image to appear as though it's "lighting up" during the animation. The best way to create this effect is to use two different shades from the same "triangle" of the color wheel.

There are two ways to go about this that generally create very effective results. One is to start with a color from the inner band of triangle, and "light up" the image using a color from one of the middle bands of the triangle. Using the red triangle as an example, you would use burgundy (from the inner band of the triangle) as the "lights off" color, and use pure red (from the middle band of the triangle) as your "lights on" color. Another option is to use the pure red from the middle band of the triangle as your "lights off" color, and use the pink from the outer band of the triangle as your "lights on" color.

When 256 Colors Isn't Enough

I ran into a fairly common problem when saving my color wheel bitmap to the GIF format: I ran out of colors. The image contains 42 different shades of red, orange, yellow, green, blue, and purple. These 42 colors are not a problem, since GIF can handle 256 colors. The problem came into the picture due to the use of a black border around each of the 42 colors. This meant that PhotoImpact had to anti-alias 42 different colors against a black border. The result was an image with several hundred colors.

When I saved the image to the GIF format, I had a serious problem: A Color Wheel with missing colors.

As you can see, the outermost band of the red, orange, and yellow triangles were all replaced with the same color. And the outermost band of the green triangle lost its pastel green color entirely and turned white.

To solve the problem, I tried favoring different color channels in the PhotoImpact Image Optimizer. In most cases, this simple step would have solved the problem. Unfortunately, it didn't work this time. Every time I would correct the problem in one color channel (such as red) I would create the same problem in another color channel (such as blue).

Next, I tried dithering. This is another step that would have worked almost every time. But, dithering does not work well in images that contain repeated use of solid colors. The dithering created a pattern of dots that may have gone unnoticed on most images, but which was painfully obvious on an image with so many blocks of solid color.