Rendering same object on two cameras with different shaders/properties

I have two cameras rendering the left and respectively right sides of the screen.

I'm rendering a (tk2d) tilemap on both sides of the screen. Now I'd like to make some changes to the way it's being rendered on each side - so the left side and right side have a different accent color. Considering it's one object with one material and one shader, is there any shader/camera trickery I can do to avoid completely duplicating the entire tilemap?

I was thinking of modifying the shader code, but not sure how to detect which camera is currently rendering? I see I can access the camera position but it feels hacky to determine which camera based on a world position.

Any other ideas? I looked at SetReplacementShaders but not sure if that would work either.