We can achieve diffuse color boost through material calculations, there are indirect methods (not a direct setting), which work well for color bleeding. However, the Lumen diffuse color boost (correct me if I’m wrong) derives its effect from the scene color captured via ray tracing or distance fields, not the materials themselves. In Unreal 5.6, it appears to also amplify direct lighting and other non-material sources, which shouldn’t be influenced by material-side calculations.
Moreover, material calculations alone shouldn’t introduce the color noise issues seen in 5.6. The problem isn’t with the equation itself unless the equation was incorrect in 5.5 and earlier versions.
Yes, the documentation has long advised against using values above 2, but this recommendation has been around since 5.1. I don’t believe 5.6 suddenly makes that guidance newly relevant or justifies the behavioral shift we’re seeing. In fact, even values as low as 1.2 can break a scene now. So the argument that “you’re just using it wrong” falls apart when identical values behave differently across versions.
Additionally, the suggestion to “just tweak exposure” entirely misses the point. You’re not trying to correct a photometric imbalance. You’re deliberately exploring artistic lighting paths that require nuanced bounce control. Exposure tweaks cannot replicate that level of intent.
It’s not just about photometric correctness. It’s about the posterization, oversaturated color bleeding, and low-light breakdown Lumen exhibits in 5.6. These issues weren’t present in 5.5 or prior versions. Yes, there are workarounds, and these problems may go unnoticed in well-lit or default scenarios, but they severely restrict creative direction when exploring non-standard or mood-driven lighting.
Also, in my second set of screenshots (Second Post), I’m not using any post-process settings. This is Lumen in its raw form.