GREG uses 24 colors for the pencils. Colors 0-7 are fixed colors, with the following values:
0 Black or White (depending on window background color) 1 Red 2 Green 3 Blue 4 Cyan 5 Yellow 6 Magenta 7 White or Black (the window background color)Colors 8-23 can be modified by the user through the P_HUE, P_SATURATION, P_VALUE arrays and LUT /PEN command, in the same way as the bitmap colors. The default values for these arrays correspond to grey intensities from white to black.