Textures with colors that are clearly wrong are surely a video driver/card problem, or a problem with FSX settings, can't be caused in any way by the scenery, and surely not across the whole sim.
The only thing that might affect the whole sim, is the fact that KLAX installer enabled HD textures in 4096x4096 format, which are required by the scenery to display at its full resolution. If you are low on VRAM or your video card/driver has issues working with such texture size (it shouldn't, unless it's very old), they might cause problems.
See what happens if you disable the "HD textures" on the Addon Manager menu, if the problem goes away, then it's sure it was a video card problem.
