IRC formatting characters

irc_formatting_characters.md

IRC formatting characters

\x02	bold
\x03	color (mIRC extension, followed by FG or FG,BG where FG and BG consist of one or two digits)
\x0f	reset (mIRC extension)
\x12	reverse
\x1f	underline

Obscure (used by which clients?)

\x11	fixed
\x16	reverse
\x1d	italic

mIRC colors

00	white
01	black
02	blue (navy)
03	green
04	red
05	brown (maroon)
06	purple
07	orange (olive)
08	yellow
09	light green (lime)
10	teal (a green/blue cyan)
11	light cyan (cyan) (aqua)
12	light blue (royal)
13	pink (light purple) (fuchsia)
14	grey
15	light grey (silver)

WeeChat at first used \x12 for reverse, but as of version 0.4.3 replaced it with \x16 instead:

core: replace default key Ctrl+c, r by Ctrl+c, v for reverse video in messages
[...]
irc: use color code 0x16 (ctrl-v) for reverse video in messages
WeeChat Changelog