This page provides information about a strange colors issue in the VFB that my occur and how to resolve it.
Overview
In some rare cases, the rendered image in the VFB might appear like the gamma is burnt out, which causes the colors of the highlights to appear bizarre or “broken”.
Often the sky is most prominently affected, showing as a different color.
Here we explore what causes the issue and how to solve it.
Cause and solution
The cause for the colors to appear like this lies in an involuntarily enabled Color Clamping button in the V-Ray Frame Buffer.
The Force Color Clamping button is located at the bottom toolbar of the VFB. It is the second icon from left to right, indicated by 3 stripes - red, green and blue.
The Force Color Clamping is a non-destructive tool, which can be enabled and disabled at any time to give insight on where the highlights are overexposed.
Example
Please note that this example uses extreme settings to showcase the behavior.