Image the most godly, glorious taste you can think of. Like, a unicorn steak prepared by the greatest chef in the universe and seasoned with rainbows and diamonds- No, stop it, what you're thinking? That's wrong. I can tell you're imagining the taste of whipped cream. Let me try again. Imagine the taste of pure beauty, as though a unicorn, nay, a rainbow itself has been grilled to a beautiful color and has then been seasoned with the tears of Aphrodite before being roasted over flames of molten gold, gold that comes from the gates of the finest palaces in the world, and which is garnished with shining delights that make the most rare gems pale in comparison- Darn it, now you're imagining whipped cream again. This is hopeless. The taste was indescribably magnificent; really, you can only learn from experience.
Now I'm trying to envision the taste of grilled Rainbow, and somehow ending up in a minefield of "light dressing" diet-food jokes.
Grilled rainbow is usually found on the "Here's the skinny!" and "Healthier options" portion of the menu. Unfortunately, it's typically so low in calories that it is placed under the "Drinks" section as water, an unfortunate mistake that has resulted from its general removal from the restaurant world following a series of lawsuits by high-status businessmen who reported, well, multicolored side effects after drinking water at certain establishments.