When going underwater, there is a drastic color change in the water. There is more of a purple tint to the water. I'm unsure if this is a bug because my brother, a friend, and I have this purple tint but when watching YouTubers, the water isn't different from 1.16 water texture. I have provided a screenshot of what I see (disclaimer: the screenshot discolors the purple tint to a dark blue but evidence of the tint is visible around the sand blocks).
There were water changes in version 1.16.230.54:
Underwater visibility has been improved
Underwater color has been tuned to better match Java Edition with a richer blue tint