The color relationship that takes design from A to A+

I was recently reviewing a student's "Nifty Shades of Grey" homework assignment. The instruction is to design a simple calculator with three different color schemes (neutral grey, warm or cool grey, and a fully "colorful" grey that incorporates lighter and darker variants). This student nailed it. All three looked fantastic, yet one stood out as very, very harmonious. Can you tell which one?

I do a lot of design critiques. Sometimes there's plenty of feedback I can give. Things that are clearly off, alignment issues, spacing problems, color contrast, typography choices.

And then there are designs like this where I'm just grasping at straws to give any kind of feedback because everything is already working so well. My critique shifts to those nearly imperceptible distinctions that separate good from great. At this level, it's all really subjective, so you might have a different opinion.

All three of these designs execute the fundamentals well. They're professionally done, clean, sophisticated work.

The monochrome version on the left and the cool purple version on the right both look great. But they don't quite achieve the same level of harmony the middle one does. The monochrome goes darker, using true black for those operator buttons. The purple maintains good contrast, but something about the overall balance doesn't quite click the same way.

The middle one achieves something different. Every hue, the brightness and the saturation are just dialed in. And there is something about the relationship between the orange and the warmer brown that really elevates it. That specific color relationship takes it from an A design to an A+.

Next time you're evaluating your own work, look for these kinds of relationships. The balance, the harmony, the subtle decisions that elevate everything.

Prefer to see this review in action? Here's the Instagram Reel.