Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce MX130/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 442.19
Broken: version: 2.82 (sub 7), branch: master, commit date: 2020-02-12 16:20, hash: rB77d23b0bd76f
Short description of error
Once the saturation of the base color in the Principled BSDF reach 1, the color will remain in the "Diffuse Direct/ Indirect", "Glossy Direct/Indirect" (if the metalic value is not 0). If you enable those passes in "Render Layer Properties" Tab, and hit render, and go to the compositor, you can see these passes in the final render is actually pure white.
Exact steps for others to reproduce the error
Based on the attched .blend file, which is a cube and a plane with a red default Principled BSDF Material. And the Viewport Shading Render Passes is currently set to "Diffuse Direct".
- Toggle renderded view, since it is currently set to "Diffuse Direct", you should normally see a white cube and a white plane, but you only see them being red.
- In the Shader Editor down below, change the saturation of the base color to any value other than 1, you can see the two becomes white.
- Turn the saturation back to 1. I have already enabled the passes in "Render Layer Properties" tab, so you only need to hit render image.
- After rendering, go to the compositor, you can see the "Diffuse Direct" pass is linked to a viewer node, so you can see the pass in the background. The pass displays a white cube and a white plane.