#237B9F
Closest named color: Ocean (#017B92). oklch(54.9% 0.097 230.3), rgb(35, 123, 159).
Aa
White text reads best on this color (4.76:1).
About this color
#237B9F is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.097 and its hue 230°. Its hue sits on the cool side of the wheel. The nearest named color is Ocean (#017B92), ΔE 0.025 away. White text reads best on it, at 4.76:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.097) |
| Temperature | cool |
| Nearest name | Ocean (#017B92) |
| Black text | 4.40:1 |
| White text | 4.76:1 |
Values
| HEX | #237B9F |
| RGB | rgb(35, 123, 159) |
| HSL | hsl(197, 64%, 38%) |
| OKLCH | oklch(54.9% 0.097 230.3) |
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 #237B9F | 4.76:1 | AA | Lc -78.2 | Fine for body text |
| Black text on #237B9F | 4.40:1 | AA large text | Lc 31.3 | Non-text elements, placeholder text |
| #237B9F text on white | 4.76:1 | AA | Lc 72.7 | Content text, not long reading |
| #237B9F text on black | 4.40:1 | AA large text | Lc -29.0 | Dividers and decoration only |
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
#F2F6F9
oklch(97.1% 0.006 239.8)
-
Step 100
100
#E2ECF1
oklch(93.7% 0.013 228.9)
-
Step 200
200
#CADDE6
oklch(88.6% 0.024 227.8)
-
Step 300
300
#A5C6D8
oklch(80.8% 0.044 231.9)
-
Step 400
400
#72A9C4
oklch(70.7% 0.07 230.2)
-
Step 500
500
#4993B5
oklch(63% 0.089 230.3)
-
Step 600
600 (this color)
#237B9F
oklch(54.9% 0.097 230.3)
-
Step 700
700
#17698A
oklch(49% 0.09 230.8)
-
Step 800
800
#175670
oklch(42.7% 0.075 230.3)
-
Step 900
900
#1B475B
oklch(37.7% 0.059 230.9)
-
Step 950
950
#112A35
oklch(27.1% 0.037 229)
#237B9F 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) | #6979A1 | 0.067 |
| Deuteranopia (no green cones) | #586D9E | 0.058 |
| Tritanopia (no blue cones) | #008587 | 0.057 |
| Achromatopsia (no color) | #737373 | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #237B9F
#237B9F
oklch(54.9% 0.097 230.3)
- #9E5F3A
#9E5F3A
oklch(54.8% 0.097 50.1)
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 #237B9F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Ocean #017B92 ΔE 0.025
- Cerulean #457B9D ΔE 0.025
- Sea Blue #047495 ΔE 0.028
- Nice Blue #107AB0 ΔE 0.028
- Dull Blue #49759C ΔE 0.031
- Muted Blue #3B719F ΔE 0.032
- Ocean Blue #03719C ΔE 0.034
- Flat Blue #3C73A8 ΔE 0.034
Use #237B9F 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.