I've found out that silicone is not the best sealer. Some surfaces it doesn't stick, some it sticks too well and you can't get it off. If you don't get it right the first time, the additional silicone doesn't stick to the old silicone.
I prefer to use 3M 4000 as a general purpose sealer. You can remove it, either by cutting or DeBond. In addition it doesn't turn color, to a light brown.
Boris