While (human) vision is 3 colors, reviews of visual arts obviously can't just describe the colors of the thing. It also has shape, depth, style, etc.

Food reviewers don't note the levels of salt, sour, etc. They describe flavors and textures and parings.

But also, I don't buy that taste is just the composition of 5 components. This sounds like a reference to that diagram of the tongue we've all seen. It's as complex as scent is. There's no way you can define the taste of cinnamon by specifying some sort of 5-tuple.