#1B3965
Closest named color: Marine Blue (#01386A). oklch(34.6% 0.085 258), rgb(27, 57, 101).
Aa
White text reads best on this color (11.53:1).
About this color
#1B3965 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.085 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.020 away. White text reads best on it, at 11.53:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.085) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.81:1 |
| White text | 11.53:1 |
Values
| HEX | #1B3965 |
| RGB | rgb(27, 57, 101) |
| HSL | hsl(216, 58%, 25%) |
| OKLCH | oklch(34.6% 0.085 258) |
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 #1B3965 | 11.53:1 | AAA | Lc -100.0 | Preferred for body text |
| Black text on #1B3965 | 1.81:1 | Fails | Lc 7.6 | Not readable |
| #1B3965 text on white | 11.53:1 | AAA | Lc 96.3 | Preferred for body text |
| #1B3965 text on black | 1.81:1 | 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
#E2EBF7
oklch(93.7% 0.019 255.5)
-
Step 200
200
#CBDAF1
oklch(88.4% 0.036 258.9)
-
Step 300
300
#A7C2EA
oklch(80.8% 0.064 258.1)
-
Step 400
400
#78A2E0
oklch(70.7% 0.102 258)
-
Step 500
500
#558AD7
oklch(63.1% 0.13 257.7)
-
Step 600
600
#3972C5
oklch(55.6% 0.142 258)
-
Step 700
700
#2C5FAA
oklch(49.1% 0.132 258.2)
-
Step 800
800
#254E8A
oklch(42.7% 0.11 258.1)
-
Step 900
900 (this color)
#1B3965
oklch(34.6% 0.085 258)
-
Step 950
950
#152740
oklch(27.1% 0.053 256.9)
#1B3965 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) | #253D67 | 0.018 |
| Deuteranopia (no green cones) | #193664 | 0.010 |
| Tritanopia (no blue cones) | #00434A | 0.067 |
| Achromatopsia (no color) | #393939 | 0.085 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B3965
#1B3965
oklch(34.6% 0.085 258)
- #4E3400
#4E3400
oklch(34.7% 0.072 77.9)
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 #1B3965, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.020
- Prussian Blue #1D3557 ΔE 0.025
- Marine #042E60 ΔE 0.042
- Twilight Blue #0A437A ΔE 0.043
- Dark Blue Grey #1F3B4D ΔE 0.045
- Midnight Green #073B4C ΔE 0.050
- Dark Grey Blue #29465B ΔE 0.053
- Charcoal #264653 ΔE 0.061
Use #1B3965 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.