#1B3175
Closest named color: Marine Blue (#01386A). oklch(34% 0.12 266.4), rgb(27, 49, 117).
Aa
White text reads best on this color (12.04:1).
About this color
#1B3175 is a dark, moderately saturated blue. In OKLCH its lightness is 34%, its chroma 0.120 and its hue 266°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.033 away. White text reads best on it, at 12.04:1.
| Hue family | Blues |
| Lightness | dark (34%) |
| Chroma | moderately saturated (0.120) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.74:1 |
| White text | 12.04:1 |
Values
| HEX | #1B3175 |
| RGB | rgb(27, 49, 117) |
| HSL | hsl(225, 63%, 28%) |
| OKLCH | oklch(34% 0.12 266.4) |
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 #1B3175 | 12.04:1 | AAA | Lc -100.7 | Preferred for body text |
| Black text on #1B3175 | 1.74:1 | Fails | Lc 0.0 | Not readable |
| #1B3175 text on white | 12.04:1 | AAA | Lc 97.1 | Preferred for body text |
| #1B3175 text on black | 1.74:1 | 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
#F2F5FE
oklch(97% 0.012 271.3)
-
Step 100
100
#E2EAFC
oklch(93.6% 0.026 266.6)
-
Step 200
200
#CAD9FB
oklch(88.5% 0.05 266.5)
-
Step 300
300
#A6C0FC
oklch(81% 0.09 266.3)
-
Step 400
400
#779CFA
oklch(70.7% 0.144 266.5)
-
Step 500
500
#5680F7
oklch(63.1% 0.184 266.5)
-
Step 600
600
#3D66E6
oklch(55.6% 0.2 266.4)
-
Step 700
700
#3054C8
oklch(49.2% 0.185 266.4)
-
Step 800
800
#2845A2
oklch(42.7% 0.154 266.6)
-
Step 900
900 (this color)
#1B3175
oklch(34% 0.12 266.4)
-
Step 950
950
#15234B
oklch(26.9% 0.076 266.7)
#1B3175 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) | #003B77 | 0.030 |
| Deuteranopia (no green cones) | #003274 | 0.019 |
| Tritanopia (no blue cones) | #00424E | 0.095 |
| Achromatopsia (no color) | #363636 | 0.120 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1B3175
#1B3175
oklch(34% 0.12 266.4)
- #483500
#483500
oklch(34.1% 0.07 86.3)
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 #1B3175, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.033
- Marine #042E60 ΔE 0.044
- Twilight Blue #0A437A ΔE 0.050
- Prussian Blue #1D3557 ΔE 0.056
- Midnight Blue #191970 ΔE 0.059
- Royal #0C1793 ΔE 0.074
- Cobalt #1E488F ΔE 0.075
- Dark Blue Grey #1F3B4D ΔE 0.082
Use #1B3175 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.