#337F9D
Closest named color: Cerulean (#457B9D). oklch(56.2% 0.087 227.5), rgb(51, 127, 157).
Aa
Black text reads best on this color (4.66:1).
About this color
#337F9D is a medium-dark, moderately saturated teal or cyan. In OKLCH its lightness is 56%, its chroma 0.087 and its hue 228°. Its hue sits on the cool side of the wheel. The nearest named color is Cerulean (#457B9D), ΔE 0.018 away. Black text reads best on it, at 4.66:1.
| Hue family | Teals and cyans |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.087) |
| Temperature | cool |
| Nearest name | Cerulean (#457B9D) |
| Black text | 4.66:1 |
| White text | 4.50:1 |
Values
| HEX | #337F9D |
| RGB | rgb(51, 127, 157) |
| HSL | hsl(197, 51%, 41%) |
| OKLCH | oklch(56.2% 0.087 227.5) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #337F9D | 4.50:1 | AA | Lc -76.5 | Fine for body text |
| Black text on #337F9D | 4.66:1 | AA | Lc 33.1 | Non-text elements, placeholder text |
| #337F9D text on white | 4.50:1 | AA | Lc 71.0 | Content text, not long reading |
| #337F9D text on black | 4.66:1 | AA | Lc -30.7 | Non-text elements, placeholder text |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 600.
-
Step 50
50
#F2F6F8
oklch(97.1% 0.005 228.8)
-
Step 100
100
#E2ECF0
oklch(93.7% 0.012 223.5)
-
Step 200
200
#CBDCE4
oklch(88.4% 0.021 227.6)
-
Step 300
300
#A7C6D5
oklch(80.9% 0.04 228.7)
-
Step 400
400
#77A9BF
oklch(70.7% 0.062 227.2)
-
Step 500
500
#5093AF
oklch(63% 0.08 227.3)
-
Step 600
600 (this color)
#337F9D
oklch(56.2% 0.087 227.5)
-
Step 700
700
#226984
oklch(49% 0.081 227.5)
-
Step 800
800
#1F566C
oklch(42.7% 0.067 228.1)
-
Step 900
900
#204757
oklch(37.7% 0.052 227.4)
-
Step 950
950
#142A33
oklch(27.1% 0.033 226.5)
#337F9D with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #6F7D9F | 0.064 |
| Deuteranopia (no green cones) | #60729D | 0.055 |
| Tritanopia (no blue cones) | #008889 | 0.052 |
| Achromatopsia (no color) | #777777 | 0.087 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #337F9D
#337F9D
oklch(56.2% 0.087 227.5)
- #9F6547
#9F6547
oklch(56.3% 0.087 47.8)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #337F9D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cerulean #457B9D ΔE 0.018
- Stormy Blue #507B9C ΔE 0.027
- Teal Blue #01889F ΔE 0.029
- Ocean #017B92 ΔE 0.031
- Dull Blue #49759C ΔE 0.032
- Blue NCS #118AB2 ΔE 0.039
- Metallic Blue #4F738E ΔE 0.040
- Nice Blue #107AB0 ΔE 0.040
Use #337F9D in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.