How can I select multiple materials that are the same, but have a different name

I have impored a illustration from Illustrator as an SVG
I convert the curves to a mesh, then join everything, remove doubles and extrude the illustration, which is a simple logo.

The logo consists of only 4 different colors. But Blender is reading every layer of the original illustration, as a seperate area for a material. What happens is, that even though the logo is only 4 colours (black, white and 2 different reds)… the logo ends up with a bunch of different materials slots, each for the layers that were used in Illustrator. All are just a diffuse color per layer.

Now, i want to turn materialize the logo and give it some texture. (turn it into a stone logo) Normally, I would only have to change 4 materials…but now I have all these different slots…of which many are the same.

My question is… how do I select the materials/slots that are the same (they just have a different name), so I can apply 1 material to them all at once.

I guess It’s not blender thats reading every layer as different material. It’s the SVG itself.
Did you use adobe Illustrator for export?

If you are familiar with HTML structure you can open the svg in some text editor and with Find and replace tool you can remove unwanted classes

You can also just delete all materials in blender and add them manually