Why 216 web-safe colors?

6 levels × 6 levels × 6 levels fill the RGB cube exactly: dense enough to show structure, sparse enough to stay readable.

Why is one corner gray?

The R=G=B diagonal is the neutral axis — the grayscale from black to white is a straight line through the cube, made visible.

RGB is the hardware space (how screens emit light); OKLCH is the perceptual space (how eyes see). Compare them in the OKLCH editor.

216 web-safe colors arranged as a 3D cube. Drag to rotate and see the structure of color space; click any point for its full profile.

Drag to rotate · hover to select · click for profile

216 points

216 web-safe colors placed by RGB coordinates — color space finally has a shape.

01
Drag to rotate
Hold and drag the canvas. Edge-on views show channel planes; diagonal views reveal the lightness axis.
02
Read the structure
R/G/B axes are the three channels — away from the origin is the direction of additive mixing.
03
Click a point
Hover any dot for its HEX and profile link; click to open the full color profile page.

Three questions for first-time cube readers.

Why 216 web-safe colors?: 6 levels × 6 levels × 6 levels fill the RGB cube exactly: dense enough to show structure, sparse enough to stay readable.
Why is one corner gray?: The R=G=B diagonal is the neutral axis — the grayscale from black to white is a straight line through the cube, made visible.
How does this differ from OKLCH space?: RGB is the hardware space (how screens emit light); OKLCH is the perceptual space (how eyes see). Compare them in the OKLCH editor.

Feel perceptual uniformity in the OKLCH editor.

Tune L / C / H in the perceptually uniform OKLCH space with live preview and oklch() / HEX / RGB output.

OKLCH perceptually-uniform gradients, no gray band, one-click CSS export.

Simulate 8 types of color vision deficiency to audit accessibility.