[dirt33]

I use clear, and it turns quite dark over time as well. The last few jobs I have done, I used Proflex clear. Within 6 months, it is dark (about the color of the caulk around your fresh water tank inlet in your photo above). All of the areas on my TT that were caulked from the factory still look much better (7 years later) than some of the caulk I have put on just in the last year. Sure would like to know what the pros use, and how it stays mostly clean-looking for so long...