OKLCH vs HSL vs RGB: Which Color Space Should You Use?
RGB describes how displays emit light, HSL rearranges that into hue-saturation-lightness for human convenience, and OKLCH models how humans actually see. This guide compares all three on the properties that decide real design work — and is honest about where the older notations still win.
Last updated: 2026-10-07 · Maintained by the OKLCH Colors team
The Short Answer
- Start new color systems in OKLCH. Perceptual uniformity means lightness, scales and contrast behave predictably, and the notation is future-proof (Baseline, wide-gamut-ready, Tailwind v4's default).
- Read HSL where you inherit it. It is serviceable for quick tweaks and still universal, but its lightness is unreliable — any automated scale built on it will drift.
- Keep RGB for the boundaries. Canvas, WebGL, image data and existing hex tokens speak RGB; convert at the edge rather than throughout your stylesheet.
OKLCH vs HSL vs RGB — Full Comparison
| Property | OKLCH | HSL | RGB |
|---|---|---|---|
| Perceptual uniformity | Yes — equal numbers look equal | No — lightness is distorted per hue | No — channels are device physics |
| Lightness you can trust | Yes — 50% is 50% for every hue | No — 50% yellow ≈ white, 50% blue ≈ dark | No lightness channel at all |
| Wide gamut (Display-P3) | Yes | No — sRGB only | No — sRGB only |
| Gradient interpolation | Even ramps with in oklch | Hue path is arbitrary | Muddy midtones between saturated colors |
| Deriving a lighter shade | Adjust L, keep C and H | Adjust L — but the result is not uniform | No single channel maps to "lighter" |
| Syntax | oklch(L C H) | hsl(H S% L%) | rgb(R G B) or hex |
| Browser support | Baseline since May 2023 | Universal | Universal |
| Typical home | Design systems, Tailwind v4 | Legacy stylesheets, quick tweaks | Canvas APIs, device output, hex tokens |
The Same Lightness Steps: HSL vs OKLCH
Both rows below walk the identical lightness values — 20, 35, 50, 65, 80 — for the same yellow hue. In OKLCH each step is a fixed perceptual increment, so the row reads as an evenly spaced ramp. In HSL the top steps crowd toward white while the bottom steps bunch into darkness, because HSL's lightness is channel math, not perception:
The same trap appears at a single value: HSL hsl(60 100% 50%) yellow and hsl(240 100% 50%) blue both claim 50% lightness, yet one reads as near-white glare and the other as a deep dark. OKLCH resolves this — a color at 50% lightness carries the same perceived brightness whatever its hue, which is what makes it safe to generate palettes from numeric rules.
Why RGB Is a Different Kind of Value
RGB is not a failed competitor — it is a different category. rgb(255 0 0) states how hard each channel drives on an sRGB display; it makes no claim about how bright or saturated the result looks, because that depends on the eye, not the signal. Two consequences follow:
- "Lighter" has no channel. Making an RGB color lighter means raising all three numbers by an amount that differs per hue — which is exactly the guesswork HSL was invented to avoid, and OKLCH actually solves.
- Interpolation is physical, not perceptual. An RGB gradient between saturated red and blue passes through a desaturated midpoint because channel math says so, not because the eye wants it.
HEX is RGB with different packaging — #ff0000 and rgb(255 0 0) are the same color. Every argument here about RGB applies equally to hex codes.
When to Stay with HSL or RGB
- Reading or writing APIs that demand RGB. Canvas
getImageData, WebGL uniforms, and most charting libraries take 0-255 channels — convert OKLCH → RGB at that boundary. - Handing colors to tools that only parse hex. Design tokens in Figma plugins, older build pipelines, or brand guidelines fixed on hex values: keep the system in OKLCH, export HEX.
- Small, hand-tuned one-offs. A single border color tweaked by eye does not need a color space argument — HSL's hue dial is quick and fine.
- Auditing legacy code. When you cannot change a stylesheet, understanding HSL's distortions is enough to predict where its scales misbehave.
The rule of thumb: keep your system OKLCH, convert at the edges. Every converter on this site exists for exactly those boundary crossings.
Moving an Existing Palette to OKLCH
- Convert each base color to
oklch()— the round trip is lossless for sRGB colors, so nothing visibly changes on day one. - Rebuild shades from lightness steps instead of inherited hex values. This is where the improvement shows: equal L steps finally look equal.
- Re-check contrast with a real ratio — perceptual lightness makes WCAG results far more predictable, but always verify rather than assume.
- Leave RGB/HEX exports in place for tools that need them; they are derived artifacts now, not the source of truth.
Frequently Asked Questions
Is OKLCH always better than HSL?
For building and maintaining color systems, yes — perceptual uniformity fixes real defects in HSL's lightness. For quick hand tweaks or code that must speak HSL, the difference rarely matters. "Better" here means predictable under automation, not invalid.
Why does HSL lightness fail?
HSL derives lightness from RGB channel values rather than from vision: lightness is the midpoint between the strongest and weakest channel. Human brightness perception doesn't work that way, so equal HSL lightness numbers deliver very different perceived brightness across hues.
Do I lose colors by moving from RGB to OKLCH?
No, going the other way can only expand: OKLCH encodes everything sRGB can (round-trips are lossless) plus colors beyond it. The one clamp happens converting a wide-gamut OKLCH value down to sRGB, where chroma is reduced to the nearest displayable color.
Are OKLCH gradients really different?
Yes. Interpolating in OKLCH keeps lightness and chroma moving evenly, so a two-color ramp stays vivid through the midpoint. The equivalent RGB ramp desaturates in the middle because channel averaging pulls toward gray. Write linear-gradient(in oklch, ...) to get the perceptual path.
Which notation should new projects use?
OKLCH for everything inside the design system, with RGB/HEX conversions only at tool boundaries. It is Baseline-supported, wide-gamut ready, and already the default palette notation of Tailwind CSS v4 — the direction the ecosystem is going.