Protanopia is a type of color blindness caused by the absence of red-sensitive cones. Reds appear very dark or black, and reds and greens may look similar.

How does protanopia differ from deuteranopia?

Both affect red-green discrimination, but protanopia also greatly reduces the perceived brightness of red light, making reds appear much darker than normal.

What percentage of people have protanopia?

Protanopia affects about 1% of males. A milder form, protanomaly, affects an additional 1% of males.

Should I avoid red and green in UI design?

Avoid using red and green alone to convey meaning. Add icons, patterns, or labels so the information is accessible regardless of color perception.

Color Blindness Simulator - Protanopia

Upload an image or palette to see how it looks to someone with protanopia.

Simulates how this color appears with Protanopia (red-blind).

Color

Original

Protanopia (red-blind)

Last updated: 2026-06-09 · Reviewed by Nham Vu