AdiIRC supports control codes for formatting text.
Colorchar $chr](3) - Ctrl + K - Colors blocks of text.<br />Boldchar [[$chr(2) - Ctrl + B - Makes the block bold.
Italicchar $chr(29) - Ctrl + I - Makes the block italic.
Underlinechar $chr(31) - Ctrl + U - Makes the block underline.
Stopchar $chr(15) - Ctrl + O - Stops all formatting.
Alternative colorchar $chr(61442) - Alternative way to show any color.