#237DBE
Closest named color: Windows Blue (#3778BF). oklch(57% 0.129 245.4), rgb(35, 125, 190).
Aa
Black text reads best on this color (4.74:1).
About this color
#237DBE is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.129 and its hue 245°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.017 away. Black text reads best on it, at 4.74:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.129) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.74:1 |
| White text | 4.42:1 |
Values
| HEX | #237DBE |
| RGB | rgb(35, 125, 190) |
| HSL | hsl(205, 69%, 44%) |
| OKLCH | oklch(57% 0.129 245.4) |
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 #237DBE | 4.42:1 | AA large text | Lc -75.7 | Fine for body text |
| Black text on #237DBE | 4.74:1 | AA | Lc 33.8 | Non-text elements, placeholder text |
| #237DBE text on white | 4.42:1 | AA large text | Lc 70.2 | Content text, not long reading |
| #237DBE text on black | 4.74:1 | AA | Lc -31.4 | 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
#E1EBF5
oklch(93.5% 0.017 248)
-
Step 200
200
#C8DCEE
oklch(88.5% 0.033 245.3)
-
Step 300
300
#A2C5E4
oklch(80.8% 0.058 245.3)
-
Step 400
400
#6EA7D7
oklch(70.8% 0.093 245)
-
Step 500
500
#4390CC
oklch(63.1% 0.118 244.9)
-
Step 600
600 (this color)
#237DBE
oklch(57% 0.129 245.4)
-
Step 700
700
#0C65A0
oklch(49.1% 0.121 245.7)
-
Step 800
800
#105381
oklch(42.7% 0.099 244.9)
-
Step 900
900
#174568
oklch(37.7% 0.078 245.2)
-
Step 950
950
#0F293D
oklch(27.1% 0.049 244.3)
#237DBE 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) | #5E80C1 | 0.053 |
| Deuteranopia (no green cones) | #4872BD | 0.037 |
| Tritanopia (no blue cones) | #008D95 | 0.091 |
| Achromatopsia (no color) | #787878 | 0.129 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #237DBE
#237DBE
oklch(57% 0.129 245.4)
- #A96500
#A96500
oklch(57% 0.127 65.6)
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 #237DBE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.017
- Nice Blue #107AB0 ΔE 0.025
- Water Blue #0E87CC ΔE 0.031
- Steel Blue #4682B4 ΔE 0.035
- Cool Blue #4984B8 ΔE 0.038
- Flat Blue #3C73A8 ΔE 0.040
- Blue NCS #118AB2 ΔE 0.046
- Muted Blue #3B719F ΔE 0.053
Use #237DBE 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.