#237FC5
Closest named color: Windows Blue (#3778BF). oklch(57.9% 0.136 246.7), rgb(35, 127, 197).
Aa
Black text reads best on this color (4.91:1).
About this color
#237FC5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.136 and its hue 247°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.021 away. Black text reads best on it, at 4.91:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.136) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.91:1 |
| White text | 4.27:1 |
Values
| HEX | #237FC5 |
| RGB | rgb(35, 127, 197) |
| HSL | hsl(206, 70%, 45%) |
| OKLCH | oklch(57.9% 0.136 246.7) |
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 #237FC5 | 4.27:1 | AA large text | Lc -74.6 | Content text, not long reading |
| Black text on #237FC5 | 4.91:1 | AA | Lc 35.0 | Non-text elements, placeholder text |
| #237FC5 text on white | 4.27:1 | AA large text | Lc 69.1 | Content text, not long reading |
| #237FC5 text on black | 4.91:1 | AA | Lc -32.6 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E1EBF5
oklch(93.5% 0.017 248)
-
Step 200
200
#C8DCEF
oklch(88.5% 0.034 246.8)
-
Step 300
300
#A1C5E6
oklch(80.8% 0.061 246.3)
-
Step 400
400
#6CA6DA
oklch(70.6% 0.098 246.7)
-
Step 500
500
#418FD0
oklch(63.1% 0.125 246.7)
-
Step 600
600 (this color)
#237FC5
oklch(57.9% 0.136 246.7)
-
Step 700
700
#0565A3
oklch(49.2% 0.125 246.3)
-
Step 800
800
#0D5284
oklch(42.6% 0.104 246.7)
-
Step 900
900
#16456A
oklch(37.8% 0.081 246.2)
-
Step 950
950
#0F283E
oklch(26.9% 0.052 247.6)
#237FC5 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) | #5E82C8 | 0.052 |
| Deuteranopia (no green cones) | #4674C4 | 0.036 |
| Tritanopia (no blue cones) | #009099 | 0.096 |
| Achromatopsia (no color) | #7A7A7A | 0.136 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #237FC5
#237FC5
oklch(57.9% 0.136 246.7)
- #AB6800
#AB6800
oklch(57.8% 0.128 66.9)
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 #237FC5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.021
- Water Blue #0E87CC ΔE 0.022
- Nice Blue #107AB0 ΔE 0.036
- Steel Blue #4682B4 ΔE 0.038
- Cool Blue #4984B8 ΔE 0.039
- Blue NCS #118AB2 ΔE 0.049
- Flat Blue #3C73A8 ΔE 0.050
- Off Blue #5684AE ΔE 0.057
Use #237FC5 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.