Purple water

Whenever I go on gm_excess_construct and go to the pointless area, the water is purple there. This also happens in gm_ocean and other water-related maps, why is that?

A. you do not have the appropiate textures.
B. The map
C. You do not have The Orange box.

A: I have the appropriate textures, I’ve confirmed that.
B: I downloaded the map.
C: I have the valve complete pack.

Go into console and type “Buildcubemaps” without the quotation marks.

The pink and black square mean you don’t have the appropiate texture. Go to gmod.org and search your map name and look if ther’s not texture fix or something like that