#1B3365
Closest named color: Marine Blue (#01386A). oklch(33.2% 0.093 263), rgb(27, 51, 101).
Aa
White text reads best on this color (12.29:1).
About this color
#1B3365 is a dark, moderately saturated blue. In OKLCH its lightness is 33%, its chroma 0.093 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.021 away. White text reads best on it, at 12.29:1.
| Hue family | Blues |
| Lightness | dark (33%) |
| Chroma | moderately saturated (0.093) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.70:1 |
| White text | 12.29:1 |
Values
| HEX | #1B3365 |
| RGB | rgb(27, 51, 101) |
| HSL | hsl(221, 58%, 25%) |
| OKLCH | oklch(33.2% 0.093 263) |
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 #1B3365 | 12.29:1 | AAA | Lc -101.3 | Preferred for body text |
| Black text on #1B3365 | 1.70:1 | Fails | Lc 0.0 | Not readable |
| #1B3365 text on white | 12.29:1 | AAA | Lc 97.8 | Preferred for body text |
| #1B3365 text on black | 1.70:1 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E3EAF8
oklch(93.6% 0.02 264.5)
-
Step 200
200
#CCDAF4
oklch(88.6% 0.039 262.9)
-
Step 300
300
#A9C1EF
oklch(80.9% 0.07 263.3)
-
Step 400
400
#7BA0E6
oklch(70.7% 0.111 262.5)
-
Step 500
500
#5A86DF
oklch(63% 0.143 263.1)
-
Step 600
600
#416ECD
oklch(55.6% 0.155 263.2)
-
Step 700
700
#335CB1
oklch(49.2% 0.143 262.9)
-
Step 800
800
#2A4B90
oklch(42.7% 0.121 263.1)
-
Step 900
900 (this color)
#1B3365
oklch(33.2% 0.093 263)
-
Step 950
950
#172543
oklch(26.9% 0.059 264)
#1B3365 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) | #193867 | 0.015 |
| Deuteranopia (no green cones) | #093264 | 0.016 |
| Tritanopia (no blue cones) | #003F47 | 0.076 |
| Achromatopsia (no color) | #353535 | 0.093 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B3365
#1B3365
oklch(33.2% 0.093 263)
- #473200
#473200
oklch(33.3% 0.068 82.8)
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 #1B3365, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.021
- Prussian Blue #1D3557 ΔE 0.027
- Marine #042E60 ΔE 0.028
- Twilight Blue #0A437A ΔE 0.055
- Dark Blue Grey #1F3B4D ΔE 0.055
- Midnight Green #073B4C ΔE 0.058
- Space Cadet #2B2D42 ΔE 0.064
- Gunmetal #293241 ΔE 0.065
Use #1B3365 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.