how to do color separation in specular reflections

Does anybody know if it’s possible to have a material’s specular reflections be different colors, sort of like what you would see in a puddle of oil or something?
This is more or less what I’m looking for:
I did this in Blender using the color ramp on the specularity, applied on a quad with a dragon-scales normal map. But I have no idea how to do it in Unity.
I’ve looked in the documentation in the section about shaders, but I can’t find anything about that kind of color separation. If I want to get this effect, will I have to write my own shader? I don’t know anything about writing shaders.

Use the standard shader with specular setup, then plug texture into specular input. The Specular levels for the material are controlled by the color (rgb) channels of the texture, and the Smoothness levels for the material are controlled by the Alpha channel of the same texture.

Note: This will not be physically accurate because the color won’t change based on viewing angle.

Let me know if this helps :wink: