Question 1

Why is OKLCH perceptually uniform?

Accepted Answer

OKLCH is built on the OKLab color space, which is designed so that equal numeric steps look like equal visual steps. Fixing the L (lightness) value keeps every color at the same perceived brightness, so the hues differ only in color, not in light/dark — which makes them easier to tell apart and looks balanced.

Question 2

What are the three main types of color vision deficiency?

Accepted Answer

Protan (red-weak/blind), deutan (green-weak/blind), and tritan (blue-weak/blind). Protan and deutan are the most common and both affect red–green discrimination; tritan is rarer and affects blue–yellow. The simulation lets you preview how your palette looks to each type.

Question 3

How many colors can people actually tell apart?

Accepted Answer

For category coding, roughly 7–12 colors is a practical ceiling — beyond that, neighbors start to blur, especially for colorblind viewers. If you need more categories, add a second cue such as shape, icon, or a number instead of more hues.

Question 4

Why add a shape or number to each color?

Accepted Answer

About 1 in 12 men and 1 in 200 women have some color vision deficiency. Encoding category with color alone can be ambiguous for them. Pairing color with a redundant cue — a shape, icon, label, or number — makes the design readable for everyone.

Question 5

What is the HSL lightness illusion?

Accepted Answer

In HSL, two colors with the same L value can look very different in brightness — yellow appears much lighter than blue at the same HSL lightness. OKLCH fixes this because its lightness matches human perception, so a fixed L really does produce equally bright colors.

Distinct Colors Generator