Duane
@HoodLily
I think your variegated zinnia is stunning and well worth propagating and preserving going forward!! It's very healthy and looks strong. Not all variegated plants are good growers.
I'd let that bud flower and go to seed. Its possible variegation will show up in the seedlings, given the extent and regularity of variegation. It will be interesting to see the flower colors!
It's definitely the kind of chimeral variegation that could get lost during the growth processes going forward. I see 2 branches starting? The lower one looks mostly green and the upper one largely white. Let any branches grow and watch them. If any change to producing all-green leaves, pinch those off at that point.
Zinnias are easy to root, even in water. It's better to root them in potting mix. You could cut off a section 6" long or so, remove the bottom leaves, and push the bottom 1-1/2-2" into the moist potting mix. You could cover it with a plastic bag for a week or so. Keep the potting mix moist but not soaking wet. It shouldn't need rooting hormone although it wouldn't be harmful if you want to give it a kickstart. You could practice on one of your regular zinnias.
Please keep posting pictures of it!!
And I should add - those bouquets are gorgeous!!
Pat