Irssi's colors that you can use in text formats, hilights, etc. :

                           text            text            background
   ---------------------------------------------------------------------
   %k      %K      %0      black           bold black      black
   %r      %R      %1      red             bold red        red
   %g      %G      %2      green           bold green      green
   %y      %Y      %3      yellow          bold yellow     yellow
   %b      %B      %4      blue            bold blue       blue
   %m      %M      %5      magenta         bold magenta    magenta
   %p      %P              magenta (think: purple)
   %c      %C      %6      cyan            bold cyan       cyan
   %w      %W      %7      white           bold white      white
   %n      %N              Turn off all colors and other formatting
   %F                      Blinking on/off (think: flash)
   %U                      Underline on/off
   %8                      Reverse on/off
   %9      %_              Bold on/off
   %:                      Insert newline
   %|                      Marks the indentation position
   %%                      A single %

 In .theme files %n works a bit differently. See default.theme
 for more information.


 MIRC colors that you can use when writing text to channel:

               foreground (fg)     background (bg)
   -------------------------------------------------------
    0          white               black 	with 0 as fg
				   light gray 	with fg > 0
    1          ligh gray           black
    2          blue                blue
    3          green               green
    4          light red           red		+ blinking fg
    5          orange              orange
    6          magenta (purple)    magenta
    7          red                 red
    8          yellow              orange	+ blinking fg
    9          light green         light green	+ blinking fg
    10         cyan                cyan		
    11         light cyan          cyan		+ blinking fg
    12         light blue          blue		+ blinking fg
    13         light magenta       magenta	+ blinking fg
    14         gray                black	+ blinking fg 
    15         light gray          black on black
                                   gray  on light gray (with bold)

 These colors may differ depending on your terminal.

 How to use these colors ('#' means a number as MIRC color code):
 
 <Ctrl>-b        set bold
 <Ctrl>-c#[,#]   set foreground and optionally background color
 <Ctrl>-o        reset all formats to plain text
 <Ctrl>-v        set inverted color mode
 <Ctrl>-_        set underline
 <Ctrl>-7        same as <Ctrl>-_
 
 To reset a mode set it again, f.e.
   <Ctrl-C>3<Ctrl-V>FOO<Ctrl-V>BAR
 creates black on green FOO followed by a green on black BAR