#237CCE
Closest named color: Windows Blue (#3778BF). oklch(57.7% 0.15 251), rgb(35, 124, 206).
Aa
Black text reads best on this color (4.84:1).
About this color
#237CCE is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.150 and its hue 251°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.025 away. Black text reads best on it, at 4.84:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.150) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.84:1 |
| White text | 4.33:1 |
Values
| HEX | #237CCE |
| RGB | rgb(35, 124, 206) |
| HSL | hsl(209, 71%, 47%) |
| OKLCH | oklch(57.7% 0.15 251) |
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 #237CCE | 4.33:1 | AA large text | Lc -75.0 | Fine for body text |
| Black text on #237CCE | 4.84:1 | AA | Lc 34.6 | Non-text elements, placeholder text |
| #237CCE text on white | 4.33:1 | AA large text | Lc 69.5 | Content text, not long reading |
| #237CCE text on black | 4.84:1 | AA | Lc -32.1 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E1EBF7
oklch(93.6% 0.019 252.9)
-
Step 200
200
#C8DCF2
oklch(88.6% 0.037 250.8)
-
Step 300
300
#A1C4EB
oklch(80.8% 0.067 251.4)
-
Step 400
400
#6CA5E2
oklch(70.7% 0.108 251.1)
-
Step 500
500
#418DD9
oklch(63.1% 0.137 250.9)
-
Step 600
600 (this color)
#237CCE
oklch(57.7% 0.15 251)
-
Step 700
700
#0762AC
oklch(49.1% 0.14 251.1)
-
Step 800
800
#0E508B
oklch(42.6% 0.116 251.2)
-
Step 900
900
#16436F
oklch(37.6% 0.09 251.1)
-
Step 950
950
#0F2841
oklch(27.1% 0.056 250.6)
#237CCE 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) | #5482D1 | 0.045 |
| Deuteranopia (no green cones) | #3872CC | 0.027 |
| Tritanopia (no blue cones) | #00909B | 0.111 |
| Achromatopsia (no color) | #797979 | 0.150 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #237CCE
#237CCE
oklch(57.7% 0.15 251)
- #A76B00
#A76B00
oklch(57.8% 0.124 71.1)
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 #237CCE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.025
- Water Blue #0E87CC ΔE 0.031
- Nice Blue #107AB0 ΔE 0.048
- Steel Blue #4682B4 ΔE 0.053
- Cool Blue #4984B8 ΔE 0.053
- Flat Blue #3C73A8 ΔE 0.059
- Mid Blue #276AB3 ΔE 0.060
- Royal Blue #4169E1 ΔE 0.062
Use #237CCE 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.