i don't know for sure but:

i've got loads of places for filler and of two or so basic colours, but even these have variations. i bought a tube of neutral water based filler and made a sample board w/ 6 different mixtures of this filler plus varying amts of sawdust and glue. from almost no dust to 100%dust(and glue).

my presumption is(haven/t done it,maybe wrong) that if i wipe the area to be filled w/ a damp cloth and then do the colour match, that that will give a close idea to what'll happen when epoxied.

i don't know what'll happen, but in some areas grain lines were apparent and so i continued them w/ exacto cuts in the filler(and into the wood somewhat to blur the intervention) and then filled the cuts w/ the 100% dust to simulate grain lines going thru the filler.

BS i know, but if one has sharp curves coming in at odd angles, lesser woodworkers need a helping hand at the intersections. (especially if mistakes in setup are made - let me count the ways!)

we'll see. but the idea of colour swatches right in front of you and different mixes has got to help. like all the strips are not one colour.

-mick

by the way, i was just foolin'. filler? me? ha!!