I'm red-green colorblind, and the best color-based systems have a few things in common:<p>1) High contrast colors<p>2) Unique icons assigned per color<p>3) They use traditional color intensity conventions<p>Usually, I can differentiate red and green by using intensity conventions. Red should be dark, and green should be bright. Visual cues help too: emergency colors should be red and white no matter what the object is. Interestingly, I can't tell blue, purple, and pink apart to save my own life.<p>To me, the system presented in the article is more-or-less garbage, since it doesn't provide an orientation and doesn't put any constraints on the contrast difference between the presented colors. I might get it right, but I'd waste a lot of time compared to a well-defined contrast system<p>I would most easily identify a system using black, white, light gray, dark red, bright green, and blue. Anything past that, and I'd start to have some problems. Pink might look like blue, yellow might look like bright green, brown might look like red, etc.<p>Sometimes I get false positives using my system: 3 years ago I found out that the Canadian flag is red and white, and not green and white. My friends and I were celebrating Canada Day as an excuse to have a party (nothing personal, Canada!), and I was explaining my color differentiation system, and very strongly asserted that the Canadian flag is green and white because it had a leaf. They spent a few moments exchanging "Is he serious? Because he looks serious" glances before spending a good 15 minutes openly mocking me.