You can embed a JavaScript function xxxShade(x,y) on the page, which returns a color (like '#ffc080'). (Where xxx is the value of the satellite parameter.) Which will then be used for the square with internal coordinates (x,y). (Where the lower-left corner is (0,0).)
The problem with coordinates is that these are not just for dressing up the image, but are used in notation. By allowing arbitrary coordinate labels it would be possible to define coordinates for which SAN can no longer be unambiguously parsed.
You can embed a JavaScript function xxxShade(x,y) on the page, which returns a color (like '#ffc080'). (Where xxx is the value of the satellite parameter.) Which will then be used for the square with internal coordinates (x,y). (Where the lower-left corner is (0,0).)
The problem with coordinates is that these are not just for dressing up the image, but are used in notation. By allowing arbitrary coordinate labels it would be possible to define coordinates for which SAN can no longer be unambiguously parsed.