Amiga Halfbrite mode
Appearance
Extra Half-Brite (EHB) mode is a screenmode of the Amiga micro computer. It uses 6 bitplanes (6 bits/pixel), where the first 5 bitplanes index a color from the color palette (consisting of 32 colors). If the bit on the 6th plane is set the color brightness is halved for each color component. This way 64 simultaneous colors are possible while only using 32 color palette registers.
The 32 colors per palette is a hardware limitation for the pre-AGA chipsets of the Amiga computer.
See also: Hold And Modify