#237AAC
Closest named color: Nice Blue (#107AB0). oklch(55.3% 0.111 239.3), rgb(35, 122, 172).
Aa
White text reads best on this color (4.71:1).
About this color
#237AAC is a medium-dark, moderately saturated blue. In OKLCH its lightness is 55%, its chroma 0.111 and its hue 239°. Its hue sits on the cool side of the wheel. The nearest named color is Nice Blue (#107AB0), ΔE 0.009 away. White text reads best on it, at 4.71:1.
| Hue family | Blues |
| Lightness | medium-dark (55%) |
| Chroma | moderately saturated (0.111) |
| Temperature | cool |
| Nearest name | Nice Blue (#107AB0) |
| Black text | 4.45:1 |
| White text | 4.71:1 |
Values
| HEX | #237AAC |
| RGB | rgb(35, 122, 172) |
| HSL | hsl(202, 66%, 41%) |
| OKLCH | oklch(55.3% 0.111 239.3) |
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 #237AAC | 4.71:1 | AA | Lc -77.8 | Fine for body text |
| Black text on #237AAC | 4.45:1 | AA large text | Lc 31.7 | Non-text elements, placeholder text |
| #237AAC text on white | 4.71:1 | AA | Lc 72.4 | Content text, not long reading |
| #237AAC text on black | 4.45:1 | AA large text | Lc -29.3 | 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
#E2EBF3
oklch(93.6% 0.015 244.7)
-
Step 200
200
#C9DCEA
oklch(88.5% 0.028 239.7)
-
Step 300
300
#A4C6DE
oklch(81% 0.05 239)
-
Step 400
400
#71A8CD
oklch(70.7% 0.079 238.8)
-
Step 500
500
#4891C1
oklch(63% 0.103 240)
-
Step 600
600 (this color)
#237AAC
oklch(55.3% 0.111 239.3)
-
Step 700
700
#156795
oklch(49% 0.104 239.9)
-
Step 800
800
#165479
oklch(42.6% 0.086 240.2)
-
Step 900
900
#1A4661
oklch(37.7% 0.067 239.1)
-
Step 950
950
#112939
oklch(27% 0.042 240.1)
#237AAC 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) | #627AAE | 0.058 |
| Deuteranopia (no green cones) | #506EAB | 0.047 |
| Tritanopia (no blue cones) | #00878B | 0.075 |
| Achromatopsia (no color) | #737373 | 0.111 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #237AAC
#237AAC
oklch(55.3% 0.111 239.3)
- #A16025
#A16025
oklch(55.2% 0.111 59)
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 #237AAC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Nice Blue #107AB0 ΔE 0.009
- Flat Blue #3C73A8 ΔE 0.023
- Muted Blue #3B719F ΔE 0.030
- Cerulean #457B9D ΔE 0.034
- Dull Blue #49759C ΔE 0.035
- Windows Blue #3778BF ΔE 0.035
- Ocean Blue #03719C ΔE 0.037
- Steel Blue #4682B4 ΔE 0.039
Use #237AAC 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.