DIY penetrative wood stain (rainbow colours)

School holiday project for my daughter, let's build a skateboard. Sure, how hard can that be and good excuse to pick myself up a vacuum press (Roarockit USA)
The challenge is she has mandated the veneer (Canadian maple) stack represent a rainbow.
Initial small scale testing with DIY stains (food colouring + rubbing alcohol) seemed promising and allowed me to get correct colour saturation. Large scale results were initially promising too, right up to the shaping began... Colour penetration wasn't consistent.
I could revert to additional coats on the next attempt but I don't like the amount of rippling and warping that the stain recipe causes to the thin veneers, cross grain layers were worst affected.
Anyone able to offer up any alternative mixes? I'm about to give fabric dye + natural oil a whirl but open for other suggestions.

I would be chasing solvent based stains. Not sure about the availability of the full range of primary colours but try this company first. http://www.polycure.com.au/polycures-water-based-and-solvent-based-dye-stains/

If they can't help they may be able to point you in the right direction. I suspect minimum quantities might be problematic.

Good luck.

mick

Thanks Mick, a little bit of trolling other forums and I've got some other alternatives. Most of which involve prolonged soaks under vacuum to achieve solid results. Given the sizing of veneers (300 X 1200) I'm looking at having to fab up some custom tanks.
Another solution was to prep the wood using a lye bath to remove all the tennans from the veneer. Needs to maintain a stabilised heat for the duration, so again not a simple backyard weekend project.
I'm going to resort to buying pre-dyed veneer but finding local products in the desired size and wood is becoming tedious.
Thanks for the help tho.