To Change the Color Depth of the Image
In the display window, choose the appropriate item from the Image menu's Color Mode submenu:
| Color Mode > | Used to: |
|---|---|
| RGB | Change the color depth to 24 bits (256 red, 256 green, 256 blue) for 16.7 M possible colors |
| 16 Colors | Change the number of colors to 16 (4-bit color depth) |
| 256 Colors | Change the number of colors to 256 (8-bit color depth) |
| Grey Scale | Process all colors to the closest grayscale value (256 shades of gray) |
| Monochrome | Process all colors (or grays) to 1-bit or black-and-white (using extreme dithering) |