What caulk color is this

I wouldn't use this product. Its easy to remove caulk by hand. In only a few cases does it really need to be completely gone, such as for painting and significant fixture changes. Usually caulk is removed and then immediately covered back up with new caulk.

I would use a plastic scraper to get the caulk up. For stubborn or detailed work use a new, clean razorblade. After the big bits are up, hit it mildly abrasive kitchen cleaner and a scrubby/rough-texture sponge to get the last little bits and adhesive up. Wipe it dry and put down new caulk.

Use the $6 you saved on the caulk remover to buy yourself lunch.

While I'm tempted to say the difference is just marketing hype, you can use either one, there is a very slight difference in formulation. The window and door stuff has slightly less petroleum distillates in the formula, according to MSDS information at nih.gov. Petroleum distillates will evaporate during curing, so I'm unsure why there's a difference. The difference is so small however, I'm confident you can use one or the other with no noticeable difference in the final installation.