#1B5181
Closest named color: Light Navy (#155084). oklch(42.5% 0.098 249.1), rgb(27, 81, 129).
Aa
White text reads best on this color (8.26:1).
About this color
#1B5181 is a dark, moderately saturated blue. In OKLCH its lightness is 42%, its chroma 0.098 and its hue 249°. Its hue sits on the cool side of the wheel. The nearest named color is Light Navy (#155084), ΔE 0.007 away. White text reads best on it, at 8.26:1.
| Hue family | Blues |
| Lightness | dark (42%) |
| Chroma | moderately saturated (0.098) |
| Temperature | cool |
| Nearest name | Light Navy (#155084) |
| Black text | 2.54:1 |
| White text | 8.26:1 |
Values
| HEX | #1B5181 |
| RGB | rgb(27, 81, 129) |
| HSL | hsl(208, 65%, 31%) |
| OKLCH | oklch(42.5% 0.098 249.1) |
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 #1B5181 | 8.26:1 | AAA | Lc -92.9 | Preferred for body text |
| Black text on #1B5181 | 2.54:1 | Fails | Lc 15.8 | Dividers and decoration only |
| #1B5181 text on white | 8.26:1 | AAA | Lc 88.2 | Fine for body text |
| #1B5181 text on black | 2.54:1 | Fails | Lc -13.9 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
Step 100
100
#E2EBF5
oklch(93.6% 0.017 250.8)
-
Step 200
200
#CADBEE
oklch(88.5% 0.032 251.1)
-
Step 300
300
#A5C4E5
oklch(80.9% 0.058 250.2)
-
Step 400
400
#73A5D7
oklch(70.6% 0.091 249.2)
-
Step 500
500
#4C8ECD
oklch(63.1% 0.117 249.2)
-
Step 600
600
#2C77BA
oklch(55.6% 0.127 249.2)
-
Step 700
700
#1E64A0
oklch(49.2% 0.118 248.9)
-
Step 800
800 (this color)
#1B5181
oklch(42.5% 0.098 249.1)
-
Step 900
900
#1D4468
oklch(37.7% 0.076 248.9)
-
Step 950
950
#12283D
oklch(27% 0.048 249)
#1B5181 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) | #3B5483 | 0.034 |
| Deuteranopia (no green cones) | #2C4A80 | 0.023 |
| Tritanopia (no blue cones) | #005C63 | 0.070 |
| Achromatopsia (no color) | #4E4E4E | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B5181
#1B5181
oklch(42.5% 0.098 249.1)
- #6E4300
#6E4300
oklch(42.4% 0.092 69)
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 #1B5181, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Light Navy #155084 ΔE 0.007
- Deep Sea Blue #015482 ΔE 0.013
- Dusk Blue #26538D ΔE 0.023
- Light Navy Blue #2E5A88 ΔE 0.035
- Cobalt #1E488F ΔE 0.038
- Twilight Blue #0A437A ΔE 0.046
- Denim Blue #3B5B92 ΔE 0.052
- YInMn Blue #415A77 ΔE 0.054
Use #1B5181 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.