#237DB1
Closest named color: Nice Blue (#107AB0). oklch(56.3% 0.114 239.6), rgb(35, 125, 177).
Aa
Black text reads best on this color (4.63:1).
About this color
#237DB1 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 56%, its chroma 0.114 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Nice Blue (#107AB0), ΔE 0.013 away. Black text reads best on it, at 4.63:1.
| Hue family | Blues |
| Lightness | medium-dark (56%) |
| Chroma | moderately saturated (0.114) |
| Temperature | cool |
| Nearest name | Nice Blue (#107AB0) |
| Black text | 4.63:1 |
| White text | 4.52:1 |
Values
| HEX | #237DB1 |
| RGB | rgb(35, 125, 177) |
| HSL | hsl(202, 67%, 42%) |
| OKLCH | oklch(56.3% 0.114 239.6) |
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 #237DB1 | 4.52:1 | AA | Lc -76.5 | Fine for body text |
| Black text on #237DB1 | 4.63:1 | AA | Lc 33.0 | Non-text elements, placeholder text |
| #237DB1 text on white | 4.52:1 | AA | Lc 71.0 | Content text, not long reading |
| #237DB1 text on black | 4.63:1 | AA | Lc -30.6 | 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
#F1F6FA
oklch(97.1% 0.008 241.7)
-
Step 100
100
#E1EBF3
oklch(93.5% 0.015 241.8)
-
Step 200
200
#C9DCEA
oklch(88.5% 0.028 239.7)
-
Step 300
300
#A3C6DF
oklch(80.9% 0.052 239.4)
-
Step 400
400
#6FA8CF
oklch(70.7% 0.083 239.4)
-
Step 500
500
#4691C2
oklch(63% 0.105 240)
-
Step 600
600 (this color)
#237DB1
oklch(56.3% 0.114 239.6)
-
Step 700
700
#106796
oklch(49% 0.106 239.8)
-
Step 800
800
#13547A
oklch(42.6% 0.088 240.2)
-
Step 900
900
#194662
oklch(37.7% 0.068 239.6)
-
Step 950
950
#102939
oklch(26.9% 0.043 239.2)
#237DB1 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) | #647DB3 | 0.059 |
| Deuteranopia (no green cones) | #5170B0 | 0.048 |
| Tritanopia (no blue cones) | #008A8F | 0.076 |
| Achromatopsia (no color) | #767676 | 0.114 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #237DB1
#237DB1
oklch(56.3% 0.114 239.6)
- #A56324
#A56324
oklch(56.3% 0.114 60)
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 #237DB1, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Nice Blue #107AB0 ΔE 0.013
- Flat Blue #3C73A8 ΔE 0.030
- Steel Blue #4682B4 ΔE 0.031
- Windows Blue #3778BF ΔE 0.031
- Cerulean #457B9D ΔE 0.036
- Blue NCS #118AB2 ΔE 0.037
- Cool Blue #4984B8 ΔE 0.038
- Muted Blue #3B719F ΔE 0.039
Use #237DB1 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.