The LCD unit of AGB can display 32 levels of red, 32 levels of green, and 32 levels of blue, for a total of 32,768 colors.
The number of colors that can be displayed at once varies with the BG mode. See "5.1.1 Details of BG Modes". Color palettes are used in defining character-format BGs and OBJs.
[Note]
Bitmap-format BG modes 3 and 5 are not palette formats. See "6.2 Bitmap Mode BG (BG Modes 3-5)".
Color palettes come in the following two forms.
This mode provides 16 color palettes, each consisting of 16 colors.
Color 0 for OBJ and BG palettes is forcibly allocated to transparent (color specification disabled).
This mode allocates all 256 of its colors to 1 palette.
Color data are represented by 15 bits (5 for Red, 5 for Green, and 5 for Blue). Colors can be selected from the total of 32,768.
OBJ color 0 and BG color 0 are forcibly allocated to transparent (color specification disabled).
Color 0 transparency is used to render the pixels of low-priority OBJs or BGs as transparent.
The color specified for color 0 of BG palette 0 is applied to the backdrop, which has the lowest priority.
OBJs and BGs use separate palettes.
The size of palette RAM is large enough (512 bytes) to hold data (16-bit) for up to 256 colors (of 32,768) that can be specified. The memory map of the OBJ and BG palettes is shown in the follow figure.
Either of 2 modes (16 colors x 16 palette and 256 colors x 1 palette) can be selected for OBJ and BG. Palette RAM for these modes is referenced as shown in the following figure.
Allows 1 of 32,768 colors to be specified.