Food colouring would work. I never tried to smoke it, It might leave a harsh smoke behind. Try it on one plant and compare. Just have some fun. It's all about having fun. I don't know why there are so many haters here trying to hate on you and your ideas. If they have some legitimate reason like they did it and it screwed up there plants or smoke then okay, but other than that, ignore them. Personally I would try it just to see what happens. I have 14 clones at the moment, maybe I'll add some to the water in one just to see what it does. It can't hurt. If it works then you impress everyone you know with your stash.
I cure my weed with all sorts. Mostly Citrus fruits, lemon, grapefruit, lime, orange, etc. It's always been great that way. The flavours pass over nicely, but if you screw up then moldy weed and kiss it good bye. I'm going to cure with Vanilla on the next round in a few jars just for fun. I don't care if people call me stupid and dumb. If I get a product that I'm happy with then great. My friends always love my crazy tasting weed and always want more. Lol, sometimes it's the samething they have just cured a little different, but they like mine more. Like I said it's just about having fun, so go enjoy yourself.
Peace.
P.S. Stop hating on the Noobs we we're all there once.