Color mode or Image mode

The color mode, or image mode, determines how the components of a color are combined, based on the number of color channels in the color model. Color modes include grayscale, RGB, and CMYK, among others. Photoshop Elements supports bitmap, grayscale, indexed, and RGB color modes.

1: RGB mode (millions of colors); 2: Index Color mode (256 colors); 3: Grayscale mode (2 colors); 4: Bitmap mode (2 colors)