#1B508F
Closest named color: Dusk Blue (#26538D). oklch(43.2% 0.118 255.1), rgb(27, 80, 143).
Aa
White text reads best on this color (8.10:1).
About this color
#1B508F is a dark, moderately saturated blue. In OKLCH its lightness is 43%, its chroma 0.118 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk Blue (#26538D), ΔE 0.014 away. White text reads best on it, at 8.10:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.118) |
| Temperature | cool |
| Nearest name | Dusk Blue (#26538D) |
| Black text | 2.59:1 |
| White text | 8.10:1 |
Values
| HEX | #1B508F |
| RGB | rgb(27, 80, 143) |
| HSL | hsl(213, 68%, 33%) |
| OKLCH | oklch(43.2% 0.118 255.1) |
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 #1B508F | 8.10:1 | AAA | Lc -92.4 | Preferred for body text |
| Black text on #1B508F | 2.59:1 | Fails | Lc 16.3 | Dividers and decoration only |
| #1B508F text on white | 8.10:1 | AAA | Lc 87.7 | Fine for body text |
| #1B508F text on black | 2.59:1 | Fails | Lc -14.5 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF7
oklch(93.6% 0.019 252.9)
-
Step 200
200
#C9DBF3
oklch(88.5% 0.038 255.6)
-
Step 300
300
#A3C3ED
oklch(80.8% 0.069 255.4)
-
Step 400
400
#71A3E4
oklch(70.7% 0.11 255.4)
-
Step 500
500
#498BDC
oklch(63.1% 0.14 254.8)
-
Step 600
600
#2973CA
oklch(55.6% 0.153 255)
-
Step 700
700
#1B60AF
oklch(49.1% 0.143 255)
-
Step 800
800 (this color)
#1B508F
oklch(43.2% 0.118 255.1)
-
Step 900
900
#1C4271
oklch(37.7% 0.092 255.2)
-
Step 950
950
#112742
oklch(27% 0.058 254.7)
#1B508F 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) | #305591 | 0.025 |
| Deuteranopia (no green cones) | #1A4B8E | 0.015 |
| Tritanopia (no blue cones) | #005F68 | 0.090 |
| Achromatopsia (no color) | #505050 | 0.118 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B508F
#1B508F
oklch(43.2% 0.118 255.1)
- #6D4800
#6D4800
oklch(43.3% 0.091 75.4)
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 #1B508F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk Blue #26538D ΔE 0.014
- Light Navy #155084 ΔE 0.019
- Cobalt #1E488F ΔE 0.023
- Deep Sea Blue #015482 ΔE 0.029
- Light Navy Blue #2E5A88 ΔE 0.039
- Denim Blue #3B5B92 ΔE 0.048
- Twilight Blue #0A437A ΔE 0.052
- Twilight #4E518B ΔE 0.058
Use #1B508F 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.