Using Material Parameters on Instances of a Static Mesh isn't as straight forward as you may think, cause Material Parameter Values won't work.
The correct way would be: "PerInstanceCustomData()" in combination with the "VertexInterpolator".
When using color-information, the "VertexInterpolator" is needed, while using a simple value to for example blend between values does not require its use.
(EXAMPLE COMING SOON)