How to change color to every specific material in a child of a group..?

Questions & Answers
1

I got this code from somewhere else.

foreach(Renderer r in target.parent.GetComponentsInChildren()) {
    	foreach(Material M in r.materials) {
    	M.color = setColor;
    	}
}

How do I make it so it only changes color to a certain material?

The material name is “Primary Color”, How do I refer to them…?
can I use string? or should I use an Index?.

2

If your script is on a gameobject, you could just make a material property and drag in the material reference in the inspector and then check in your loop if the material in the renderer is the same material.

Example:

public Material material;

public void YourFunction() {
    foreach(Renderer r in target.parent.GetComponentsInChildren()) {
            foreach(Material M in r.materials) {
                if(M == material) {
                    M.color = setColor;
                }
            }
    }
}

Edit: Actually, if they use the same material, you only need to change the color of the reference:

public Material material;

public void YourFunction() {
    material.color = setColor;
}

Now, if they don’t use the exact same material and rather its own material instance based on the same material; then I would check for the name of the material instead.