And when mode +c is activated on a channel that no coloring is allowd? maybe adding this to your script:

  if ((/ !isin $left($1,1)) && (%colorfont) && (*c* !iswmcs $chan($active).mode)) { 
    msg $chan 0,14 $Strip($1-)
    halt 
  }
  else {
  msg $chan $1-
}