Ouch, hope the pool water didn't corrode portion of the color, judging by the last picture! I'm no chemist, but perhaps rinsing the watch fast with tap water? Cheers ;-)
Not a chemical reaction. Anything red changes at even 5 feet of depth. A wet red watch not immersed in water will look the same. But when submerged it will gradually lose color the deeper you go. The bezel on the 16610LV is green more many reasons. Still ...