They patented blue eyes.
For the first few years of your life you had to pay royalties for your eye colour. If you were employed by the company, of course, they let you have blue eyes for free. Many people tried to hide their blue eyes with coloured contact lenses, but a court ruling stated that this only won them a discount, because their eyes were still blue at night.
Eventually, expensive surgeries were developed to change eye colour. In the beginning they were risky, and could only remove more pigment. Naturally blue-eyed people had their pigment entirely removed, and sported pink and violet eyes, but soon regretted their decision due to the increased photosensitivity. Brown-eyed people who were wealthy wanted blue eyes as a status symbol, and had a few layers of pigment stripped away, at the cost of some of their vision.
The truly impoverished gauged their eyes out.