Standing in the grocery store, I knew I was going to have to buy something yellow before I could leave. My basket held momen (cotton) tofu, kinugoshi (silk) tofu, enoki mushrooms, maitake mushrooms, two cucumbers and a pickled bok-choy-like vegetable. White, white, white, black, green, green. At home, I had some tomatoes and umeboshi: red, red. But I was missing yellow. The omission seemed glaring, as obvious as someone walking around stylishly dressed and pants-less. I wandered the produce section, picked up a shrink-wrapped piece of kabocha, Japanese pumpkin, and headed for the register.

There are five principles of Japanese food which outline the ideal components of every meal. Each principle is a list of five items which should all be present for a nutritionally, visually, spiritually balanced meal, with no single component overpowering the others. It’s a bit intimidating, being someone who grew up on tuna casseroles and simple Thai stir-frys, to remember the meal should, according to go hou (five ways), include an uncooked dish, a grilled dish, a steamed dish, a simmered dish and a fried dish. I haven’t gotten that far yet. I’ve only just mastered the colors.

Go shiki, five colors, says that every meal should include foods that are red, yellow, green, black and white. Not does this ensure visual interest, it also means the meal will be nutritionally balanced, since different colored foods are high in different vitamins and minerals. Since every meal includes rice, white is easy, and with all the green vegetables in the world, so is green. With my recent love of kurogoma, black sesame, it’s not hard to get black into the meal. (Deep purple foods like eggplant and dark brown foods like shiitake mushrooms also qualify as black.) Red is tricky, but I usually pull it off the with help of salmon, tomatoes, umeboshi and radishes. But yellow is always a problem.

There’s kabocha. There’s lemon. There’s a yellow daikon radish pickle called takuan. And there’s corn, which in Japan tops everything from pizza to sushi—and is usually accompanied by giant squirts of mayonnaise, I’m sorry to report. Happy as I am to have mastered go shiki, I draw the line at entering the Land of Corn while on my Japanese food journey. Instead, I’m growing some yellow nasturtiums—edible flowers with a peppery flavor—to use as garnishes for meals missing yellow.

I can’t decide if I’m crazy to think eating flowers makes more sense than eating corn and mayo. Whatever. I eat crab guts. I can draw the line wherever I want.