Tools for everyday color
These are the jobs people actually use a color-vision aid for: telling two colors apart, making a picture easier to read, and knowing which pairs usually collide.
Tell two colors apart
Pick two colors. The page says whether full color vision can separate them, and whether protan, deutan, or tritan vision still can.
Boost a picture
This shifts the color differences a chosen cone type misses into colors that stay visible. It is the same idea as the Daltonize filter used in color-assist apps. Useful for a chart, a map, or a photo where red and green mean different things.
Pairs that often collide
If a sign, chart, or outfit uses only these pairs, add a word, a shape, or a lightness difference. The names are the part that still works when the hues do not.
- Red Green The usual mix-up for red-green deficiency. Both can look brown or dull.
- Green Brown Brown is a dark red-orange, so it slides toward green.
- Blue Purple Purple is blue plus red. When red drops out, purple looks blue.
- Pink Gray A light red can lose its color and read as gray.
- Orange Yellow These stay closer than they look once red and green trade places.
- Red Black Strong protan vision sees red as darker, so a red light can disappear on a dark background.
Further reading
- National Eye Institute: color blindness — what it is, the types, and what tends to help in daily life.
- MedlinePlus Genetics — how common red-green deficiency is, by sex and ancestry.
- Color Oracle — a free desktop app that shows a whole screen the way protan, deutan, or tritan vision sees it. Handy for a friend or a designer.
- DaltonLens — names the color under the pointer and can mark matching colors in a chart.