Making me think, looking at your colors, for simple CAULIFLOWER:
Does (ANY) Gardener enthusiast tried INJECT with syringe, various (edible) FOOD COLORING ?
You know; like Lime Green Cauliflower, or...how about Blue or YELLOW Sunflower Seeds ?
Sounds pretty vain, I know, espec when others don't feed their families, in extreme poverty.
A Cobalt Blue dish, of Sunflower Seeds, would be a party staple.
Artichokes, well, you'd have to 'bleach out, the natural green, first.
Heck, I heard that BEARS, as parents; ENCOURAGE the little cubs, to play with their food.
There is, likely, a safe-consumable LUMINESCENT chemical, for safe food additives, once in a special season. People do their HAIR luminescent.
Believe it, or not, I actually have too much, imagination...But it helps drive commerce, if you get the right combo, of circumstances...