Color may just be one of the single most subjective things out there. If you’re in a room full of people and ask them for their favorite color, you’d be hard pressed to find more than one or two people whose favorites are the same color for the same reason. Despite this, there seems to be something hard-coded into our cultural DNA to have different emotional responses to different colors. For example, a danger warning will probably feel a lot more urgent if it was bright red as opposed to, say, sky blue. Chapter 4 of Paul Zelanski and Mary Pat Fisher’s book Color outlines some of the various effects color has on people. All this is to say, color will mean different things to different people, but there are a few baseline rules that are handy to follow, such as red being a much more in-your-face, loud, and urgent color than a meek dark blue.
Some designs use color in really intelligent and creative ways. Ever wonder why so many fast-food chains have red and yellow logos? It’s because those are the colors that will catch your attention first when driving, when you don’t have a lot of time to carefully look at the signs passing by. A store such as Whole Foods, on the other hand, uses green in its logo as a subtle way to drive home the whole “you’re making a healthy choice by shopping here,” as green invokes imagery of not just green veggies, but nature as a whole. Of course, you can overanalyze as many logos as you want to try to squeeze meaning out of any color, but that’s kind of the whole point: color should be thought out and intentional.
This gets us to Corporate Memphis. You’ve seen it before; think of the flat, geometric people that seemingly every company is using nowadays. Beyond my personal hatred for nearly every aspect of this art style, it objectively uses color terribly. Worse than that, it’s not just that the colors don’t have poorly thought-out meaning, they don’t have any meaning at all. Corporate Memphis’ entire justification for existing is being an inclusive, culturally neutral art style that companies can slap onto their branding and advertising to lazily imply that they are a morally good entity. Given that, their use of color makes more sense, as cultures have different ingrained connotations tied to colors, but practically, it makes for a boring, soulless design, which is a problem with the art style as a whole, but I am placing the majority of the blame on its color use.

Take this example from Facebook. Okay, based on the overall bright color scheme and body language of the characters drawn, we are clearly supposed to get a sense of fun and joy. So that begs the question, why is the violin, the “vessel of fun” of the dude smack-dab in the middle the same dark (read: NOT FUN) color as the background? Why is 80% of the second-from-the-left lady’s design taken up by purple? What’s that supposed to convey? That she’s . . . rich? Some sort of nobility? A sagely wizard? What’s the point in making the skin tone of two of the people be a direct match to the color of another’s pants? I get this nauseating feeling that the goal was to make the colors represent both everything and nothing at the same time, which is an awful idea. This is an example of bad color use, in which (in my opinion) the color choices actively detract from the design as a whole. If the colors were, god forbid, thought out, maybe this design wouldn’t make me hate Facebook even more than I already do. But, here we are, and I hate Facebook, and I hate this art style.
A good example of well-thought out colors in this art style would be anything from Youtube science channel Kurzgesagt. They use a similar art style while actually managing to convey real meaning with their color choices. Take this for example:

This is the thumbnail for the video entitled “Loneliness,” which you probably could’ve gotten just from the design. See how the meaning of the overall color scheme isn’t forcibly stripped away from it? Overanalysis time: the use of blue (a color commonly associated with sadness) corresponds with red, allowing for the purple (being both red and blue in a way) in the middle to effectively communicate that it is something that is both a part of the rest while being distinctly different, which is a common feeling that lonely people have.
This is getting too long so I’ll cut it short with a short and simple conclusion: color is good when use well, but color is really bad when used poorly.