Xerox Paris, a document system Support & Software User Guide

The Blue, Red and Green palettes provide a Black and White tile, then a further 14
tiles where the content of the primary color varies from a value of 255 to a value of
21 (default settings).

For example in the Blue Palette below [1], the selected tile has a blue value of 255,
in [2] the selected tile has a blue value of 111 and in 

[3] the selected tile has a blue

value of 21. None of the tiles have any red or green value.

The same values also apply to the green and red palettes where in the case of the
Green palette, the tiles have no red or blue values and in the Red palette the tiles
have no green or blue values.