You can't pick a signature color. You earn it.

Founders often tell me they want their own color, the way Tiffany has its blue. It's a great goal. It's just not something you choose in a design meeting. It's something you earn.

Tiffany registered its blue as a federal trademark in 1998, and the color is now a custom Pantone shade called 1837, the year the company was founded. But Tiffany had been using that robin's egg blue since the 1800s. The registration didn't create the association. It recognized one that already existed, built over well more than a century of using the same color in the same way.

Even then, there are limits

Christian Louboutin's red sole is the other famous case. In 2012 a federal appeals court agreed the red sole had become a real trademark, but only when it contrasts with the rest of the shoe. An all-red shoe with a red sole from another designer was fine. The protection wasn't the color. It was the color in a specific place, doing a specific job, that people had learned to read as Louboutin.

That's the part worth stealing. A color becomes yours through placement and repetition, long before any lawyer gets involved.

What this means for your brand

• Choose one hero color and give it a job. The inside of the box, the cap, the tissue paper, the sole. One place, every time.
• Write the color down precisely. Pantone for print, CMYK, RGB and hex for screens, and how it should look on the stocks you actually use. Drift starts when nobody wrote it down.
• Be patient and consistent. Every time you use a different shade "just this once," you spend down the recognition you're building.
• Talk to a trademark attorney if a color becomes central to the business. I'm a designer, not a lawyer, and color marks are their own area of law.

Most small brands change their colors every season to stay interesting. The ones that end up owning a color did the boring thing for years.