#37517F
Closest named color: Dusk Blue (#26538D). oklch(43.6% 0.083 261.2), rgb(55, 81, 127).
Aa
White text reads best on this color (7.93:1).
About this color
#37517F is a dark, moderately saturated blue. In OKLCH its lightness is 44%, its chroma 0.083 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk Blue (#26538D), ΔE 0.027 away. White text reads best on it, at 7.93:1.
| Hue family | Blues |
| Lightness | dark (44%) |
| Chroma | moderately saturated (0.083) |
| Temperature | cool |
| Nearest name | Dusk Blue (#26538D) |
| Black text | 2.64:1 |
| White text | 7.93:1 |
Values
| HEX | #37517F |
| RGB | rgb(55, 81, 127) |
| HSL | hsl(218, 40%, 36%) |
| OKLCH | oklch(43.6% 0.083 261.2) |
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 #37517F | 7.93:1 | AAA | Lc -92.1 | Preferred for body text |
| Black text on #37517F | 2.64:1 | Fails | Lc 16.6 | Dividers and decoration only |
| #37517F text on white | 7.93:1 | AAA | Lc 87.4 | Fine for body text |
| #37517F text on black | 2.64:1 | Fails | Lc -14.7 | Not readable |
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 800.
-
Step 50
50
#F3F6FA
oklch(97.2% 0.006 255.5)
-
Step 100
100
#E5EAF4
oklch(93.6% 0.015 264.5)
-
Step 200
200
#CFDAEB
oklch(88.5% 0.026 259)
-
Step 300
300
#AFC2E1
oklch(81% 0.049 260.2)
-
Step 400
400
#86A1D1
oklch(70.6% 0.077 261.7)
-
Step 500
500
#6789C5
oklch(63% 0.099 261.3)
-
Step 600
600
#4F73B2
oklch(55.7% 0.107 261)
-
Step 700
700
#3F6099
oklch(49.1% 0.1 260.7)
-
Step 800
800 (this color)
#37517F
oklch(43.6% 0.083 261.2)
-
Step 900
900
#2E4164
oklch(37.6% 0.065 262)
-
Step 950
950
#1B263A
oklch(26.9% 0.041 261.9)
#37517F 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) | #3F5581 | 0.017 |
| Deuteranopia (no green cones) | #364E7E | 0.009 |
| Tritanopia (no blue cones) | #0C5B62 | 0.074 |
| Achromatopsia (no color) | #515151 | 0.083 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #37517F
#37517F
oklch(43.6% 0.083 261.2)
- #694C0F
#694C0F
oklch(43.7% 0.083 80.8)
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 #37517F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk Blue #26538D ΔE 0.027
- Light Navy Blue #2E5A88 ΔE 0.028
- Light Navy #155084 ΔE 0.032
- Dusk #4E5481 ΔE 0.034
- Deep Sea Blue #015482 ΔE 0.037
- YInMn Blue #415A77 ΔE 0.037
- Twilight #4E518B ΔE 0.038
- Denim Blue #3B5B92 ΔE 0.040
Use #37517F 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.