Advantages of clear (vs. black) rust prevention

If I am going to put Waxoyl or equivalent onto areas that don’t need to have a pretty black sheen, does it make sense to use the "clear" version so that any new build up of rust can be seen when checking it – does it work like that?

I know that it’s not as tough as thick underseal but I’ve been looking at the absolute horror stories of the black stuff which looks wonderful until you find the new corrosion it’s been hiding.