LCH Color Picker

How to use the LCH color picker

1. Set lightness first to fix how light or dark the color is on the perceptual scale.
2. Raise chroma for a more vivid color, backing off when the swatch stops changing and you reach the gamut edge.
3. Turn the hue angle to choose the color while keeping lightness and chroma fixed.
4. Copy the lch() value, or send it through the Color Converter for a HEX or RGB fallback.

What is an LCH color?

LCH writes a color as lightness, chroma and hue, shaped like lch(56% 68 296). The picker maps those three onto sliders so you can build a color and copy the lch() code directly. Its numbers come from color science rather than the screen, which is why the same lightness value looks equally bright across every hue.

How LCH is built on CIELAB

LCH is the cylindrical form of CIELAB, the color space the CIE published in 1976 to model how the human eye judges the distance between two colors. CIELAB uses awkward a and b axes; LCH keeps the exact same space but swaps them for a chroma distance and a hue angle, which is far easier to dial in by hand. The format was later standardised for the web in CSS Color Level 4, so lch() now works in a stylesheet.

Reading an lch() value

How LCH differs from OKLCH: the blue problem

LCH and OKLCH use the same three labels, but they sit on different math. LCH inherits one quirk from CIELAB: as you lighten a blue, its hue drifts toward purple. OKLCH was designed in 2020 specifically to fix that. Reach for LCH when you want the long-established, color-science standard; reach for OKLCH when rock-steady hues matter more.

Delta E: the measurement LCH was made for

Because LCH is perceptual, the straight-line distance between two colors in it predicts how different they look to a person. That distance is called Delta E, and it is why labs, printers and quality checks rely on Lab and LCH rather than RGB.

Where LCH fits

• Color science and lab work, where Delta E decides whether two samples match.
• Print and packaging proofing, to keep a brand color consistent across materials.
• Data visualisation, where evenly spaced lightness keeps a sequential scale readable.
• Accessible palettes, since perceptual lightness makes contrast easier to predict.

Why LCH still earns its place

OKLCH gets most of the attention now, and for UI that is fair. But LCH is far from retired. It is built on CIELAB, the standard print and color science have trusted for decades, and it is what Delta E measurements assume. When the job is matching physical color rather than shipping a website, LCH is still the one to trust.