Switching biome will cause a fog glitch

It looks like you are using night vision in the Nether which causes the weird colors (normally the colors are blue and red). 

We are already tracking the issue @ MC-171302

I used night vision to show it

I used night vision to show it

Ah, in this case, we are tracking it @ MC-170879. As you can see, it was closed as invalid since this is more of a feature request than a bug.