Request: Add the ability for materials to take on the “layer color” of objects they are assigned to, and in the panels for specifying material properities add a “by layer” option for color/base color.
Which modes are you intending to do this in?
Rolling it into grasshopper would work in the wip.
There is the same discussion here: Convert Display Color to Render Material?
SynchronizeRenderColors?
I work in Rhino, not Grasshopper.
I’ll try it.
ObjColorAsMatColor : Applies the material color as the display color.
byRhino Gadget - Help
ObjColor2MatColor : Creates a material with the same display color; if the display standard is by layer, creates a layer material.
byRhino Gadget - Help
Would this be helpful? You can apply the layer color to the material color, or vice versa. It’s a free plugin. ‘byRhinoGadget’
@Jean-Go How is this different than SynchronizeRenderColors?
The SynchronizeRenderColors command changes an object’s material color to match its display color.
If the object does not have a material assigned, a new material will be created and assigned to the object’s layer.
I just tested it, and it does the exact same thing! 
Using the built-in SynchronizeRenderColors command without installing a plugin seems like the better way to go.