I also noticed a problem with mIRC colours in unicode. If a sentence starts with a number, the first number of that sentence is incorporated in the unicode. thus, resulting in a normal coloured sentence with the first char missing.
But after some exploring i discovered "chr(3) is the mIRC equivalent on CTRL+K".
Just prefix any mIRC colour with a value < 10 with a zero to prevent the same crap happening
chr(3).'08,04hello'; <-- yellow foreground and red background.
chr(3).'14blah blah'; <-- gray text..
Hope it helps someone.