#237FBA
Closest named color: Nice Blue (#107AB0). oklch(57.3% 0.123 242.4), rgb(35, 127, 186).
Aa
Black text reads best on this color (4.81:1).
About this color
#237FBA is a medium-dark, moderately saturated blue. In OKLCH its lightness is 57%, its chroma 0.123 and its hue 242°. Its hue sits on the cool side of the wheel. The nearest named color is Nice Blue (#107AB0), ΔE 0.022 away. Black text reads best on it, at 4.81:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | moderately saturated (0.123) |
| Temperature | cool |
| Nearest name | Nice Blue (#107AB0) |
| Black text | 4.81:1 |
| White text | 4.36:1 |
Values
| HEX | #237FBA |
| RGB | rgb(35, 127, 186) |
| HSL | hsl(203, 68%, 43%) |
| OKLCH | oklch(57.3% 0.123 242.4) |
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 #237FBA | 4.36:1 | AA large text | Lc -75.3 | Fine for body text |
| Black text on #237FBA | 4.81:1 | AA | Lc 34.3 | Non-text elements, placeholder text |
| #237FBA text on white | 4.36:1 | AA large text | Lc 69.8 | Content text, not long reading |
| #237FBA text on black | 4.81:1 | AA | Lc -31.9 | 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
#E1EBF4
oklch(93.5% 0.016 245.1)
-
Step 200
200
#C8DCEC
oklch(88.4% 0.031 242)
-
Step 300
300
#A2C6E2
oklch(81% 0.055 241.8)
-
Step 400
400
#6EA7D3
oklch(70.6% 0.088 242.7)
-
Step 500
500
#4391C8
oklch(63.2% 0.113 242.3)
-
Step 600
600 (this color)
#237FBA
oklch(57.3% 0.123 242.4)
-
Step 700
700
#09669B
oklch(49% 0.114 242.5)
-
Step 800
800
#10547E
oklch(42.8% 0.094 242.3)
-
Step 900
900
#174565
oklch(37.6% 0.074 242.9)
-
Step 950
950
#0F293B
oklch(27% 0.046 241.6)
#237FBA 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) | #6380BD | 0.057 |
| Deuteranopia (no green cones) | #4E73B9 | 0.043 |
| Tritanopia (no blue cones) | #008E94 | 0.085 |
| Achromatopsia (no color) | #797979 | 0.123 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #237FBA
#237FBA
oklch(57.3% 0.123 242.4)
- #AA6517
#AA6517
oklch(57.2% 0.123 62.4)
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 #237FBA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Nice Blue #107AB0 ΔE 0.022
- Windows Blue #3778BF ΔE 0.025
- Steel Blue #4682B4 ΔE 0.029
- Water Blue #0E87CC ΔE 0.031
- Cool Blue #4984B8 ΔE 0.033
- Blue NCS #118AB2 ΔE 0.037
- Flat Blue #3C73A8 ΔE 0.039
- Cerulean #457B9D ΔE 0.047
Use #237FBA 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.