#1B3A64
Closest named color: Marine Blue (#01386A). oklch(34.8% 0.082 256.7), rgb(27, 58, 100).
Aa
White text reads best on this color (11.43:1).
About this color
#1B3A64 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.082 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.022 away. White text reads best on it, at 11.43:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.082) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.83:1 |
| White text | 11.43:1 |
Values
| HEX | #1B3A64 |
| RGB | rgb(27, 58, 100) |
| HSL | hsl(215, 57%, 25%) |
| OKLCH | oklch(34.8% 0.082 256.7) |
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 #1B3A64 | 11.43:1 | AAA | Lc -99.9 | Preferred for body text |
| Black text on #1B3A64 | 1.83:1 | Fails | Lc 7.8 | Not readable |
| #1B3A64 text on white | 11.43:1 | AAA | Lc 96.1 | Preferred for body text |
| #1B3A64 text on black | 1.83:1 | Fails | Lc 0.0 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E2EBF6
oklch(93.7% 0.018 253.3)
-
Step 200
200
#CBDBF0
oklch(88.6% 0.034 255.2)
-
Step 300
300
#A7C3E9
oklch(80.9% 0.062 256.1)
-
Step 400
400
#78A3DE
oklch(70.8% 0.099 256.5)
-
Step 500
500
#548AD5
oklch(63% 0.128 256.9)
-
Step 600
600
#3873C2
oklch(55.6% 0.138 256.6)
-
Step 700
700
#2B60A7
oklch(49.1% 0.127 256.7)
-
Step 800
800
#254F88
oklch(42.8% 0.106 256.8)
-
Step 900
900 (this color)
#1B3A64
oklch(34.8% 0.082 256.7)
-
Step 950
950
#152740
oklch(27.1% 0.053 256.9)
#1B3A64 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) | #273D66 | 0.018 |
| Deuteranopia (no green cones) | #1C3763 | 0.009 |
| Tritanopia (no blue cones) | #00444A | 0.066 |
| Achromatopsia (no color) | #3A3A3A | 0.082 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B3A64
#1B3A64
oklch(34.8% 0.082 256.7)
- #4F3400
#4F3400
oklch(34.8% 0.073 76.9)
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 #1B3A64, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.022
- Prussian Blue #1D3557 ΔE 0.025
- Dark Blue Grey #1F3B4D ΔE 0.042
- Twilight Blue #0A437A ΔE 0.042
- Marine #042E60 ΔE 0.045
- Midnight Green #073B4C ΔE 0.048
- Dark Grey Blue #29465B ΔE 0.049
- Charcoal #264653 ΔE 0.057
Use #1B3A64 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.