I remember Alexander Tome saying he created this look
by setting the hair with gel then applying cream make-up on top from the Makeup For Ever Flash Palette (I think!). The look is not dissimilar. Hope this is helpful!
Edit - I just reread your post - the flash palette is excellent for mixing. It's pretty oily but a few shampoos with hot water should remove it. Bear in mind it will stain light or colour-treated hair, however gel would act as a barrier somewhat, if you ensured every strand was covered. It wouldn't damage the hair at all.
I'd probably get a hairstylist involved with this look if you can.