Category leaders don't pick colors to fit in — they pick them to escape comparison. The entire discipline of color strategy collapses into a single question: do you want to look like the rest of your category, or do you want to be impossible to confuse with anyone?
Color as differentiation
The founder who walks into a category and picks its dominant color is saying "I'm competing on product." Fine, if your product is actually better. But most founders discover the hard way that in a crowded shelf — or a crowded app store, or a crowded search result — product quality is very difficult to read at a glance.
Color is read instantly. It's the cheapest possible signal. And it's the one thing a competitor can't immediately copy without visibly capitulating.
The Stripe example
When Stripe picked purple in 2011, the payments category was owned by blue (PayPal, Visa, Chase) and green (Square's original hero color). Purple was unused. It was, crucially, available.
Stripe didn't pick purple because purple was strategically correct in some abstract sense. They picked it because every other color in the space was already claimed, and they wanted the founder who opened a dashboard to see something they'd never seen before.
Eleven years later, purple reads as "developer-grade payments infrastructure" in a way no word on a billboard could establish in the same time. That's the compounding return on a brave color decision made at the right moment.
What to do with this
Don't optimize your palette for "what feels right" — optimize it for what's available. Walk your category. List the dominant colors of every visible competitor. Then work outward from that list. The goal isn't to pick the most beautiful color. It's to pick the color that forces a comparison you can win.
A little more on that in the Generator, where you can see what's available in your category in about thirty seconds.