Forever White is still, er, white after a good few years. Had to redo the Dow stuff a couple of times in a similar timeframe. I'd pick the Forever stuff over the Dow for domestic internal use next time.
I dug out and replaced the bath/shower seal recently and researched which was the best anti mould sealer on the internet.
Most review's I read recommended EVERBUILD Everflex 500+. Let you know in a few years time (hopefully)
Our bathroom fitters liked to use CT1, it's not done bad but 4 years on I noticed a few black mold spots appearing along a section, I've removed and replaced it with Forever White,.......let's see how that stands up.
Don't whatever you do use unibond sealer. I used that on my shower tray and several months later some of it was still like toothpaste. Cleaned it all up and used CT1 which went off nicely in a day.