The BBj TermConsole, when run on or emulating a color capable terminal, uses 6 bit colors for the background and foreground. This means that only 2 bits each are used to describe the red, green and blue color components, resulting in a palette of 64 (4 x 4 x 4) possible colors on terminals that can support it. The eight standard color mnemonics and the 'BACKGR' mnemonic can provide up to sixteen different 6 bit colors out of this palette of 64 colors. These sixteen colors include a dim and a bright intensity of the eight pre-defined standard colors.
The BBj SysConsole and SysWindow, on the other hand, use 24 bit colors by default. This means that 8 bits are used to describe the red color component, 8 bits for the green component, and 8 bits for the blue component, resulting in a palette of more than 16.5 million (255 x 255 x 255) possible colors. Up to sixteen different 24-bit colors are available in a SysConsole / SysWindow. Typically, the definitions for these colors are a dim and a bright intensity of the eight standard colors set by a color mnemonic (black, blue, green, cyan, red, magenta, yellow, and white).
The 'RGB' mnemonic allows a programmer to create additional colors by setting the RGB values directly. In the TermConsole, this will result in a new 6 bit color, which is one of the possible 64 colors in the palette.
The only method for developers to adjustments to the TermConsole colors is via the terminal device color mnemonics previously mentioned. There is no Color Map dialog box available to tune colors.