#1B4577
Closest named color: Twilight Blue (#0A437A). oklch(38.8% 0.097 254.7), rgb(27, 69, 119).
Aa
White text reads best on this color (9.70:1).
About this color
#1B4577 is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.097 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.014 away. White text reads best on it, at 9.70:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.097) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.16:1 |
| White text | 9.70:1 |
Values
| HEX | #1B4577 |
| RGB | rgb(27, 69, 119) |
| HSL | hsl(213, 63%, 29%) |
| OKLCH | oklch(38.8% 0.097 254.7) |
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 #1B4577 | 9.70:1 | AAA | Lc -96.4 | Preferred for body text |
| Black text on #1B4577 | 2.16:1 | Fails | Lc 11.8 | Not readable |
| #1B4577 text on white | 9.70:1 | AAA | Lc 92.2 | Preferred for body text |
| #1B4577 text on black | 2.16:1 | Fails | Lc -10.2 | 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 900.
-
Step 50
50
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF8
oklch(93.6% 0.021 254.9)
-
Step 200
200
#C8DBF4
oklch(88.5% 0.04 255.3)
-
Step 300
300
#A1C4EF
oklch(81% 0.072 253.8)
-
Step 400
400
#6DA3E8
oklch(70.6% 0.117 255.1)
-
Step 500
500
#438BE1
oklch(63.2% 0.149 254.5)
-
Step 600
600
#2073CF
oklch(55.7% 0.162 254.6)
-
Step 700
700
#1060B3
oklch(49.2% 0.15 254.5)
-
Step 800
800
#124E91
oklch(42.6% 0.125 254.9)
-
Step 900
900 (this color)
#1B4577
oklch(38.8% 0.097 254.7)
-
Step 950
950
#0F2744
oklch(27% 0.062 254.6)
#1B4577 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) | #2D4979 | 0.023 |
| Deuteranopia (no green cones) | #1E4076 | 0.015 |
| Tritanopia (no blue cones) | #005158 | 0.075 |
| Achromatopsia (no color) | #444444 | 0.097 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B4577
#1B4577
oklch(38.8% 0.097 254.7)
- #5E3D00
#5E3D00
oklch(38.9% 0.082 74.7)
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 #1B4577, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.014
- Light Navy #155084 ΔE 0.036
- Cobalt #1E488F ΔE 0.041
- Deep Sea Blue #015482 ΔE 0.045
- Marine Blue #01386A ΔE 0.049
- Dark Grey Blue #29465B ΔE 0.050
- Dusk Blue #26538D ΔE 0.054
- Charcoal #264653 ΔE 0.064
Use #1B4577 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.