I think it seems to occur when you have lights (orange/yellow kind of colours only?) on your map. Basically you know how the infected have a green filter, well that filter combined with the lights makes the infected see pink/purple instead of yellow/orange. You can see this on the Drill map (look at the orange pipes, they are pink as infected) and backwoods (fire becomes pink as infected).
On the map im making this is a huge issue.
Here is the view as a human
Here is the view as the infected
Note: i did make a post about this the other day with no replys but now i photos to show