CoBlind — Color Blindness Simulator Online

Around 300 million people worldwide have some form of color blindness. Most can still see colors—just not the way you might expect. Red-green color blindness is the most common type, affecting about 8% of men and 0.5% of women with Northern European ancestry.

Here's what's happening: your retina has cone cells that detect red, green, and blue light. Most of us have all three working normally. But when one type is missing or doesn't work right, certain colors start looking the same. It's not about seeing less—it's about seeing differently.

Why does this matter for designers? Imagine you use red for errors and green for success. To someone with red-green color blindness, those might look nearly identical. That's a real usability problem you can avoid with a quick simulation.

Simulation lets you see your work through someone else's eyes—literally. It's not just about checking a compliance box. It's about catching problems before they frustrate real users.

Ever built a chart with red and green lines? Run it through a simulator and you might see those lines blending into one. That's the kind of thing you want to catch before launch, not after a user complains.

The best part? When you test early, you don't have to retrofit. Accessibility becomes part of your design process instead of an afterthought. That saves time, money, and a lot of headaches.

Whether you're designing dashboards, building apps, creating marketing graphics, or working on educational content—if color matters, simulation matters.