Solidify new material

Is it possible to make the “solidifyed” area a new material/texture? When applying the solidify modifier.

In the screenshot i have just a normal plane so it’s easy to just select the “new” area and change texture, but i need this for more complicated objects and takes long time to select each surface and change the material texture

Right there, in the modifier settings on your screenshot, there’s a Material Index Offset. With it you can assign different material slots to faces and rim faces. Just create new material slots on the object and assign relevant materials to them, and set their indices in those settings (first slot is 0, second is 1 and so on).