I'm not positive but I think black dyes are more intense in order to get the saturation? needed so it's harsher? so it may break down the wax and soak through. I'm wondering if you could use tinfoil because it has 0 absorbency and the dye may stay in the petal. Or would a cookie rack on tinfoil work? Then you could use a damp paint brush to gather up the dry drips and reuse it. Hope that helps.
 

Those were good tips and instructions for the roses. I feel inspired to come up with some alternate filter flowers for you. I was thinking of a smattering of lily of the valley... or maybe snowdrops because the paper would lend it's self well to that. It's funny you should mention pussy willows though because I spent several minutes in a store this week stroking the pussy willows and thinking how they would look in you bouquet but I didn't think you would go for it. . . I should know better by now right? I'll get some while they are in season but I think we need to glue the fuzzy bundles onto the stem because they fall off so easily. Or they could be glued on a wire stem so they could be twisted to fall in a cascade and not be so twiggy and straight. . .what do you think?
Karma
(MOTB) 

Well your new colours are very vibrant and festive looking. I'm kind of homesick for my moms rose garden. So now I know you want your paper flowers for sure we just need to figure out what colour and what else to tuck in with them. There is a lot of possibilities that will dry and keep a realistic look or we could use dried flowers. Oh I found some vines at the dollar store that would work on the pillars. 
This is all very exciting to see you come up with new ideas to make your wedding unique to you and your groom.
I'm proud of your creations but then I have a bias being Mother of the Bride.

Raine, your roses are stunning! These will be wonderful wedding decorations. I love the washes in the colouring. They remind me of my mothers roses. Where will you use them in your wedding. . . tables, arches, cars?