Palette

A selection of colours which is used in an image. Rather than defining a colour for each individual pixel (such as in 24-bit colour images), palettes are used to link pixels to colour data by way of an index reference. Graphics in Megadrive, Master System, Game Gear and GameBoy Advance games all use palettes.

Megadrive Palette

Consists of 16 colours, each represented by two bytes (four nybbles) in the format 0B GR, where B = blue; G = green; and R = red. The B, G and R can be any of the following values:

• 0 = 0
• 2 = 32
• 4 = 64
• 6 = 96
• 8 = 128
• A = 160
• C = 192
• E = 224
• (and in rare cases, F = 224)

Pixels reference these 16 colours using a single nybble. 0 refers to the 1st palettte entry (which is normally transparent), 1 refers to the second entry, and so on.

Master System Palette

Consists of 16 colours, each represented by eight bits (a single byte) in the format 00BBGGRR, where BB = blue; GG = green; and RR = red. The BB, GG and RR can be any of the following values:

• 00 = 0
• 01 = 85
• 10 = 170
• 11 = 255

As such, the highest palette value is 00111111, which is 3F when converted to a byte.