Changing color of many without editing material

Hello all, is there a way to change the color of multiple objects without having to change all their materials 1 by 1? What I am trying to achieve is making the object green if it can be placed at the current position(building system), or red if it cannot. However, right now I need to open all materials and make the color as a parameter, and it is time consuming. Is there a workaround?

You could use a Material Parameter Collection, perhaps?

Seems interesting thanks, although I was looking for a way that I don’t have to edit every single material. Like I got a campfire object with 4 different materials, and I need to edit all 4 materials just for 1 object, and it’s really time consuming. This might come in handy tho, thanks :slight_smile:

Look at postprocess materials, there is example of outline material (google it). You could modify it to cover whole mesh not only edges.

Thanks, I tried this outline material and it works great but I am having trouble making it work for the entire mesh. Could someone guide me a little bit?
This is the entire code.

and I assume some changes need to happen here:

Any tip will be appreciated :slight_smile:

Is it possible to also reduce opacity using post process? I looked in google but couldn’t find any valuable information