Pam's natural hair color, to judge from her February 1990 appearance in Playboy magazine, is brown, and that makes her a bottle blonde.
The active ingredient in hair bleach is hydrogen peroxide. This stuff is all around us, even in rain, but it's not that strong or we'd all be blondes! In fact, many mouthwashes contain hydrogen peroxide.
At the other extreme though, a strong solution of hydrogen peroxide can be used for rocket fuel!
Obviously, Pam needs something in between. And how can cosmetic companies be sure she won't harm her scalp? Animal tests of course!
Of course, we now know that a 3% solution is all Pam needs to have fun. But let's not forget all the bottle blonde bunnies that made this possible!