How about swiss chard? either bright lights (stems are yellow, pink, coral, red) or ruby swiss chard (all red stems with red veining in leaf) or purple kohlrabi-purple bulb, leaves green with purple vein-or scarlet runner beans-pole bean with wonderful red blossoms(humming birds like it) Of course, I think ALL vegetables are beautiful but I plant a few flowers among the veges. Cosmos (finches love the formed seeds) and calendula which self seeds (I have to pull some of them) and dill flowers
and red orach (use leaves for salad or steam lightly like spinach) and don't forget nasturtium with edible flowers.