White is the default color for any 1-character code not explicitly set. The files consist of 3 lines. The example maps temperature factors from deep blue to red. Values less than 7.3 are color 10 and values greater than or equal 33.4 are red. This is a binary file.
Larger values increase the scale.
Translations change this value. The identity matrix is the default. This isn't quite free-format. See also the ribbons color index scheme. You probably don't want to edit this file in general - let the program create it.