Changes

On a green screen (where all colours are shades of green), the colours (in the software/firmware BASIC colours), are in order of increasing intensity. Black is very dark, and white is bright green, and colour 13 is a medium green. (Thanks to [[Mark Rison|Mark Rison]] for this information) The luminance (Y) is not exactly correlated to the actual luminance of color images broadcast in RGB. We have other values. Amstrad preferred to propose a completely different image system, not comparable to a conversion to monochrome, which would have limited the number of brightness levels to 21 (for example, colors 9 and 6 would have had the same luminance). They opted for a table of 27 linear brightness steps. They assigned values of 1 (1kΩ) for blue, 3 (3.3kΩ) for red, and 9 (10kΩ) for green.