HEX to OKLCH: #991B1B

Result

Values are shown at full precision, so converting back gives exactly #991b1b. The rounded form is what you normally paste into CSS.

Step-by-step math

Every number below is computed from the input, nothing is looked up.

1. 1. sRGB → linear

   R: 153/255 = 0.60000 → 0.318547  (((x + 0.055) / 1.055)^2.4)
   G: 27/255 = 0.10588 → 0.010960  (((x + 0.055) / 1.055)^2.4)
   B: 27/255 = 0.10588 → 0.010960  (((x + 0.055) / 1.055)^2.4)

2. 2. linear sRGB → LMS

   l = 0.4122·R + 0.5363·G + 0.0514·B = 0.137754
   m = 0.2119·R + 0.6807·G + 0.1074·B = 0.076139
   s = 0.0883·R + 0.2817·G + 0.6300·B = 0.038121

3. 3. cube root

   l′ = ∛0.137754 = 0.516458
   m′ = ∛0.076139 = 0.423840
   s′ = ∛0.038121 = 0.336553

4. 4. LMS′ → Oklab

   L = 0.2105·l′ + 0.7936·m′ − 0.0041·s′ = 0.44369
   a = 1.9780·l′ − 2.4286·m′ + 0.4506·s′ = 0.14387
   b = 0.0259·l′ + 0.7828·m′ − 0.8087·s′ = 0.07299

5. 5. Oklab → OKLCH

   C = √(a² + b²) = 0.16132
   H = atan2(b, a) = 26.899°
   L = 0.44369

6. 6. OKLCH

   oklch(0.44369 0.16132 26.899)
   rounded: oklch(0.444 0.161 26.9)

All formats

HEX

#991b1b

RGB

rgb(153 27 27)

RGB (legacy)

rgb(153, 27, 27)

HSL

hsl(0.00 70.00% 35.29%) → hsl(0 70% 35%)

HWB

hwb(0 11% 40%)

OKLCH

oklch(0.444 0.161 26.9) · oklch(44.4% 0.161 26.9)

OKLab

oklab(0.444 0.144 0.073)

Lab (D50)

lab(33.86 50.80 35.41)

LCH (D50)

lch(33.86 61.92 34.88)

Display P3

color(display-p3 0.5506 0.1567 0.1344)

Linear sRGB

color(srgb-linear 0.3185 0.0110 0.0110)

Gamut: sRGB and Display P3

#991B1B is a hex color, so it sits inside sRGB and therefore inside Display P3. At this lightness and hue, sRGB reaches chroma 0.181 and Display P3 reaches 0.204; this color uses 89% of the sRGB chroma available.

CSS snippets

.element {
  color: #991b1b;
  color: rgb(153 27 27);
  color: hsl(0 70% 35%);
  color: oklch(0.444 0.161 26.9);
}

/* Tailwind CSS v4 */
@theme {
  --color-brand: oklch(0.444 0.161 26.9);
}
/* arbitrary values */
class="text-[#991b1b] bg-[oklch(0.444_0.161_26.9)]"

/* wide-gamut screens */
@media (color-gamut: p3) {
  .element { color: color(display-p3 0.5506 0.1567 0.1344); }
}

/* relative color syntax: 10% darker */
.element-dark { color: oklch(from #991b1b calc(l - 0.1) c h); }

Nearby colors

Closest colors in the Tailwind and CSS named palettes (OKLab distance).

• red-800#9F0712
• brown#A52A2A
• orange-800#9F2D00
• v3 rose-800#9F1239
• v3 orange-800#9A3412
• darkred#8B0000
• rose-800#A50036
• red-900#82181A

Lighter and darker, same hue and chroma

• #AE322D · oklch(0.504 0.161 26.9) · ΔL +0.06
• #850006 · oklch(0.384 0.161 26.9) · ΔL −0.06

Open in the studio