The option ‘-Cn’ sets the color mode to n, where the color modes are, briefly,
- 0
No color
- 1
ANSI color
- 2
Bilevel
- 3
Trilevel
- 4
User-defined
These modes, and color output in general, are described more thoroughly in Color.
For obscure technical reasons, this command is processed differently than all other command-line options. In the present incomplete implementation, the color mode must be set on the command line, not in .fweb! To work around this annoyance, UNIX users could alias commands such as ‘ftangle -C1’.