Above is an early version of my scene. From left to right there is the default blender plane with the default material, my custom volumetric cloud, and an element that I want to use in the scene. The lighting is an HDRI from HDRIHaven.com, and a sun lamp.
what I need is a brighter cloud material that matches the brightness of the plane and structure. I have played with all of the color and density settings, but nothing creates a brighter result than what I have above.
Density to high/thick? High Density usally make dark clouds.Put a math multiply after the colorramp and try 0.10 - 0.30
Additional,you dont have to use a principled shader into the surface.Use only the volume shader into the volume.
The extinction in a cloud is 0.005 -0.1 m^-1
if your cloud model scale is in blender units (same scale as the real cloud) this is a good start.
Then the ext cofficient works for it self at density 1.
if you have cloud model with a size of 1m IE.And you want a optic of a cloud that is 10m thick,then you have to multiply the extinction,in this case with the density.for a 10m thick cloud optic then set the density to 10.
edit,further look at these cloud vdb rendering tests,and the volume bounce settings,to get a good basis for the scattering.