22.3.1. Flat Graphical Images

Strategy: Use colors from the web palette to fill flat color areas when you are designing the image. Do not apply the strict web palette option when saving or exporting because you'll lose the gradations of color in the anti-aliasing. It is better to choose an adaptive palette with a "web snap" option, if it is available. In Photoshop, set the amount of web snap with the slider scale. In Fireworks, apply the Web Adaptive palette. This will maintain the web colors in your flat areas but allow some non-web-safe colors in the anti-aliasing and other blends to remain.

22.3.2. Photographic Images

Strategy: First, if it is an entirely photographic image, consider saving it in JPEG format. Otherwise, choose an Adaptive palette (or Perceptual in Photoshop 5.5 and up) to preserve the original color range in the image. That way, the image will look the best it possibly can for users with 16- and 24-bit monitors (the vast majority). For users with 8-bit monitors, the image will map again to the web palette, but dithering is usually not detrimental in photographic images. The only advantage to applying the web palette to a continuous-tone image in the saving process is that you know it will look equally bad to everyone.

22.3.3. Combination Images (Flat and Photographic Areas)

Strategy: Use web-safe colors in the flat areas when you are designing the image. When it's time to save or export to GIF format, choose an adaptive palette with a "web snap" option if it is available. The adaptive palette preserves the color fidelity in the photographic areas while the web snap option preserves the web-safe colors in the flat areas.