I logged into a newly generated world with a resource pack on.
I then thought ''hmmm I wonder if mojang have changed any of the default textures''
So I removed the resource pack and the water surface texture was the same as the top/bottom of a stone slab block.
This happened to all the water in the world, all of the water's other properties i.e swimming in it, drowning, blue filter when in water e.c.t stayed the same.
The lava texture was also changed to that of a lapis block.
You can still swim in lava as well as getting the red filter.
Logging in and out had no effect.

Thanks for reading c: From an otherwise very satisfied fan!