#237BAB
Closest named color: Nice Blue (#107AB0). oklch(55.5% 0.109 238), rgb(35, 123, 171).
Aa
White text reads best on this color (4.67:1).
About this color
#237BAB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.109 and its hue 238°. Its hue sits on the cool side of the wheel. The nearest named color is Nice Blue (#107AB0), ΔE 0.011 away. White text reads best on it, at 4.67:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.109) |
| Temperature | cool |
| Nearest name | Nice Blue (#107AB0) |
| Black text | 4.49:1 |
| White text | 4.67:1 |
Values
| HEX | #237BAB |
| RGB | rgb(35, 123, 171) |
| HSL | hsl(201, 66%, 40%) |
| OKLCH | oklch(55.5% 0.109 238) |
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 #237BAB | 4.67:1 | AA | Lc -77.5 | Fine for body text |
| Black text on #237BAB | 4.49:1 | AA large text | Lc 32.0 | Non-text elements, placeholder text |
| #237BAB text on white | 4.67:1 | AA | Lc 72.1 | Content text, not long reading |
| #237BAB text on black | 4.49:1 | AA large text | Lc -29.6 | 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
#E2EBF2
oklch(93.5% 0.014 241)
-
Step 200
200
#C9DCE9
oklch(88.4% 0.027 237.6)
-
Step 300
300
#A4C6DD
oklch(80.9% 0.049 237.8)
-
Step 400
400
#71A8CC
oklch(70.7% 0.078 238.1)
-
Step 500
500
#4892BF
oklch(63.2% 0.1 237.9)
-
Step 600
600 (this color)
#237BAB
oklch(55.5% 0.109 238)
-
Step 700
700
#146893
oklch(49.2% 0.101 237.7)
-
Step 800
800
#155577
oklch(42.7% 0.084 237.3)
-
Step 900
900
#1A4660
oklch(37.6% 0.065 238)
-
Step 950
950
#112938
oklch(26.9% 0.041 238.3)
#237BAB 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) | #647BAD | 0.060 |
| Deuteranopia (no green cones) | #526EAA | 0.050 |
| Tritanopia (no blue cones) | #00878C | 0.070 |
| Achromatopsia (no color) | #747474 | 0.109 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #237BAB
#237BAB
oklch(55.5% 0.109 238)
- #A26129
#A26129
oklch(55.5% 0.11 58)
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 #237BAB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Nice Blue #107AB0 ΔE 0.011
- Flat Blue #3C73A8 ΔE 0.026
- Cerulean #457B9D ΔE 0.031
- Muted Blue #3B719F ΔE 0.032
- Dull Blue #49759C ΔE 0.035
- Steel Blue #4682B4 ΔE 0.037
- Windows Blue #3778BF ΔE 0.038
- Ocean Blue #03719C ΔE 0.038
Use #237BAB 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.