teken: color #3 is yellow not brown - use TC_YELLOW as the name

[emaste]

Summary

The console escape code standard (ECMA-48) specifies color #3 (escape code 33) as yellow.

A brown console color is an artifact of the VGA palette, which replaces dim (but not bright) yellow with brown.

[imp]

seems fine...

[emaste]

sys/sys/terminal.h

97

hmm, these may appear in kernel config files. This should probably be

#define FG_YELLOW TCOLOR_FG(TC_YELLOW)
#define FG_BROWN FG_YELLOW

and below

#define FG_LIGHTYELLOW (TFORMAT(TF_BOLD) | TCOLOR_FG(TC_YELLOW))

and similar for BG_*

[emaste]

sys/sys/terminal.h

97

Probably best to leave them alone since they most likely are/were being used with VGA consoles, and already have some inconsistencies with console escape names (e.g. white)