-- Lingo syntax exit
Keyword; instructs Lingo to leave a handler and return to where the handler was called. If the handler is nested within another handler, Lingo returns to the main handler.
The first statement of this script checks whether the monitor is set to black and white and then exits if it is:
on setColors
if _system.colorDepth = 1 then exit
sprite(1).foreColor = 35
end