YES and NO.

[ghost]

It would be nice if YES and NO could be seen in a Red/Green colour.

[kolinkrewinkel]

Will look into this through a more general approach...to allow users to set custom colors for any keyword. I could see people wanting to make, say, "return" or "break" also be red or something.

[rolandleth]

This would be pretty awesome :D

edit:

Here's a temporary approach:

NSString *variable = [[self string] substringWithRange:newRange];
if ([variable isEqualToString:@"false"] || [variable isEqualToString:@"NO"] || [variable isEqualToString:@"break"] || [variable isEqualToString:@"defer"]) {
    return [NSColor colorWithCalibratedRed:0.83 green:0.45 blue:0.59 alpha:1];
}
else if ([variable isEqualToString:@"true"] || [variable isEqualToString:@"YES"] || [variable isEqualToString:@"continue"] || [variable isEqualToString:@"guard"]) {
    return [NSColor colorWithCalibratedRed:0.41 green:0.76 blue:0.57 alpha:1];
}