Just a 'Hi' as I'm new here. Also a comment about multi-colour printing.

[curious aardvark]

well depending on how youy want to do it.
make a solid tetrahedron, with recessed panes, then print 3 coloured triangles and glue them in.

The base tetrehedron colour would be the colour of the bottom face.
Otherwise you have some fairly dodgy bridging on the base - although it does depend how large the 'dice' are.

I'm shocked you'd wimp out on something like the dice :-)