how to keep materials when use realize instances - Geometry Nodes

Question

I created the geometry node according to the images below, the object I'm using in the node is this "lamp" with random color between red and white. But when I use the Realize Geometry node all the colors change only to red.

That is, I would like to know how to keep materials without geometry nodes using perform geometry.

this is without realize

this is with realize

this is the shade that I'm using

Answer 1

here is a working example in Blender 3.2

Geo node setup

Shader setup

We basically create a random value in geo nodes and pass it to the shader editor via a custom attribute ( called _id in this example), per instance. We set the material in the geo nodes and read it as a factor of the colorramp node ( set on constant).