Trying to use COLORCORE.....need help

I used a 60V bit to try and make a sample address sign. Some lines didn’t go deep enough, and it is rough looking. What bit should I be using? And how do I clean it up?

I seem to get the best results from this one.

I added a video to my reply over on FB, hopefully seeing the visual at the end with the 2 color HDPE material, adjusting the top layer thickness and the 2 different angle V bits I showed helps explain what my initial comment meant.
but the answer to clean up the carve and show more of the Blue below is to use a steeper angle V bit And/OR a material with a thinner top layer. . .

Also looking at the photo again, the perimiter seems uneven, like the surface is not parallel to the spindle’s X,Y plane of movement. (the workpiece is higher near the front of the CNC and lower nearer the rear) And here’s How I’d fix that: Surface the wasteboard OR you can try this shimming method: