VXGI : Is there any way to increse diffuse intesity (color) of movable object?

Development Rendering
1

I am working on VXGI Unreal engine.

Here is what getting using VXGI. I want to increase the color level of diffuse on a white wall.

https://forums.unrealengine.com/filedata/fetch?type=thumb&filedataid=129065

Is there any suggetion?