In color GLCDs, each individual pixel is divided into three cells, or subpixels, which are colored red (R), green (G), and blue (B).

In GLCDs, the most important thing in interfacing color GLCD is to know how color is defined to a given pixel. Available formats depends on the brand and type of GLCD controller built in the choosen module :

12 bit per pixel pixel format (12bpp)
RRRRGGGG  4 bits red and 4 bits green 1st pixel BBBBRRRR   4 bits blue 1st pixel and 4 bits red 2nd  pixel GGGGBBBB  4 bits  green and 4 bits blue 2nd pixel

8 bit per pixel pixel format (8bpp)
RRRGGGBB  3 bits red, 3 bits green and 2 bits blue

16 bit per pixel pixel format (16bpp)
RRRRRGGG  5 bits red and 3 bits green 1st pixel GGGBBBBB  3 bits red and 5 bits blue 1st pixel

The Bitmap2LCD programming tool supports these GLCD color formats from V2.0.