I was reading an article by Mark Richards on his approach to colour and methods of application.

Something he trialled was pouring paint onto the blank then running the squeegee along the blank. The areas the paint hit first were darker because the paint soaks into the foam. Result is a dick van straalen type finish

I've been thinking how to apply this to eps which is generally sealed before laminating. So has anyone been putting pigments into the qcells epoxy mix?

Here is q cell tinted filler coat I did.
Obviously not direct on blank but over carbon. The pros can get some pretty cool, swirls / colour combos with the filler coats. :))

looks great and thanks.

did you apply with a paint brush?

No
all you need is masking tape, knife and a squeegee