I think this is what you're looking for.
Code:
 on ^*:text:*:#:{
if $nick != <nick> {
echo $chan $nick $strip($1-)
}
else {
echo $chan $strip($1-)
}
haltdef
}
on ^*:action:*:#:{
if $nick != <nick> {
echo $chan $nick $strip($1-)
}
else {
echo $chan $strip($1-)
}
haltdef
}


That will strip the colour, bold, underline and reverse codes from all text and actions performed in the channel, except for the person named. Replace <nick> with the nick of the person that you want exempted.

Note: This will not work properly combined with a code that has the command /strip in the on start or on load events.