HEX to OKLCH: #155E75

Result

Values are shown at full precision, so converting back gives exactly #155e75. 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: 21/255 = 0.08235 → 0.007499  (((x + 0.055) / 1.055)^2.4)
   G: 94/255 = 0.36863 → 0.111932  (((x + 0.055) / 1.055)^2.4)
   B: 117/255 = 0.45882 → 0.177888  (((x + 0.055) / 1.055)^2.4)

2. 2. linear sRGB → LMS

   l = 0.4122·R + 0.5363·G + 0.0514·B = 0.072276
   m = 0.2119·R + 0.6807·G + 0.1074·B = 0.096886
   s = 0.0883·R + 0.2817·G + 0.6300·B = 0.144262

3. 3. cube root

   l′ = ∛0.072276 = 0.416547
   m′ = ∛0.096886 = 0.459290
   s′ = ∛0.144262 = 0.524465

4. 4. LMS′ → Oklab

   L = 0.2105·l′ + 0.7936·m′ − 0.0041·s′ = 0.45003
   a = 1.9780·l′ − 2.4286·m′ + 0.4506·s′ = -0.05518
   b = 0.0259·l′ + 0.7828·m′ − 0.8087·s′ = -0.05381

5. 5. Oklab → OKLCH

   C = √(a² + b²) = 0.07707
   H = atan2(b, a) = 224.283°
   L = 0.45003

6. 6. OKLCH

   oklch(0.45003 0.07707 224.283)
   rounded: oklch(0.450 0.077 224.3)

All formats

HEX

#155e75

RGB

rgb(21 94 117)

RGB (legacy)

rgb(21, 94, 117)

HSL

hsl(194.37 69.57% 27.06%) → hsl(194 70% 27%)

HWB

hwb(194 8% 54%)

OKLCH

oklch(0.450 0.077 224.3) · oklch(45.0% 0.077 224.3)

OKLab

oklab(0.450 -0.055 -0.054)

Lab (D50)

lab(36.50 -15.90 -19.68)

LCH (D50)

lch(36.50 25.30 231.06)

Display P3

color(display-p3 0.1757 0.3631 0.4495)

Linear sRGB

color(srgb-linear 0.0075 0.1119 0.1779)

Gamut: sRGB and Display P3

#155E75 is a hex color, so it sits inside sRGB and therefore inside Display P3. At this lightness and hue, sRGB reaches chroma 0.085 and Display P3 reaches 0.112; this color uses 91% of the sRGB chroma available.

CSS snippets

.element {
  color: #155e75;
  color: rgb(21 94 117);
  color: hsl(194 70% 27%);
  color: oklch(0.450 0.077 224.3);
}

/* Tailwind CSS v4 */
@theme {
  --color-brand: oklch(0.450 0.077 224.3);
}
/* arbitrary values */
class="text-[#155e75] bg-[oklch(0.450_0.077_224.3)]"

/* wide-gamut screens */
@media (color-gamut: p3) {
  .element { color: color(display-p3 0.1757 0.3631 0.4495); }
}

/* relative color syntax: 10% darker */
.element-dark { color: oklch(from #155e75 calc(l - 0.1) c h); }

Nearby colors

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

• cyan-800#005F78
• v3 sky-800#075985
• sky-800#00598A
• slate-600#45556C
• v3 teal-800#115E59
• teal-800#005F5A
• v3 slate-600#475569
• v3 cyan-900#164E63

Lighter and darker, same hue and chroma

• #2B6F87 · oklch(0.510 0.077 224.3) · ΔL +0.06
• #004D64 · oklch(0.390 0.077 224.3) · ΔL −0.06

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