Mold making questions

I’ve recently been commissioned to design a coaster for a local resort. If the design is approved then I’ll get the material to make a mold of it and mass produce it. It printed out well but I’m having some issues with the concept render. Because of how shallow the features are (1/8") I can’t reliably dye multiple batches of resin and pour them individually.

But I’m not sure what colors are available for the powder method. The colors I need (in hex values so you can plug them into Blender or The Gimp to see them) are DDDDFF, DDFFDD, FFDDDD, FFBEBF, B4B4FF, B4FFB4, FFB4B4, and AA9F76. I don’t know if colors like that are available in powder, it seems mixing them is just for pattern effects (faux wood and the like), and I don’t want to put anything in the concept render that can’t actually be done.

Also, are there any recommendations for materials? I’m thinking of going with Smooth On but they seem a bit expensive. I’m hoping to find something for cheaper than $153 per gallon for silicone rubber but still reliable enough that I won’t have to make a mold every five castings.

If it will help here’s a render showing the colors I need. They’re not quite the color values I posted because I had to reduce the luminance to take care of some color bleeding issues.

And just to keep up with licensing, backdrop created by David Zerba.