Remove colors to keep only a few

[Ofnuts]

Very unlikely that you can find a hidden message just by looking at specific colors. This is so dependent on the lighting used when you took the picture (direction, color temperature).

If you wan tot see grooves clearly, you to light the object from the size so that light rays are almost parallel to the surface. In the picture above the light is head on (and possibly a flash), exactly the opposite of what should be done.