#1F3378
Closest named color: Marine Blue (#01386A). oklch(34.9% 0.121 267.5), rgb(31, 51, 120).
Aa
White text reads best on this color (11.64:1).
About this color
#1F3378 is a dark, moderately saturated blue. In OKLCH its lightness is 35%, its chroma 0.121 and its hue 268°. Its hue sits on the cool side of the wheel. The nearest named color is Marine Blue (#01386A), ΔE 0.036 away. White text reads best on it, at 11.64:1.
| Hue family | Blues |
| Lightness | dark (35%) |
| Chroma | moderately saturated (0.121) |
| Temperature | cool |
| Nearest name | Marine Blue (#01386A) |
| Black text | 1.80:1 |
| White text | 11.64:1 |
Values
| HEX | #1F3378 |
| RGB | rgb(31, 51, 120) |
| HSL | hsl(227, 59%, 30%) |
| OKLCH | oklch(34.9% 0.121 267.5) |
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 #1F3378 | 11.64:1 | AAA | Lc -100.1 | Preferred for body text |
| Black text on #1F3378 | 1.80:1 | Fails | Lc 7.5 | Not readable |
| #1F3378 text on white | 11.64:1 | AAA | Lc 96.4 | Preferred for body text |
| #1F3378 text on black | 1.80:1 | 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
#A7BFFC
oklch(80.9% 0.091 267.7)
-
Step 400
400
#799CFB
oklch(70.8% 0.145 267.4)
-
Step 500
500
#597FF8
oklch(63.1% 0.185 267.7)
-
Step 600
600
#4165E7
oklch(55.7% 0.201 267.6)
-
Step 700
700
#3353C9
oklch(49.2% 0.187 267.4)
-
Step 800
800
#2A44A2
oklch(42.6% 0.155 267.5)
-
Step 900
900 (this color)
#1F3378
oklch(34.9% 0.121 267.5)
-
Step 950
950
#16234B
oklch(26.9% 0.076 267.6)
#1F3378 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) | #003D7A | 0.031 |
| Deuteranopia (no green cones) | #003577 | 0.023 |
| Tritanopia (no blue cones) | #004450 | 0.097 |
| Achromatopsia (no color) | #383838 | 0.121 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F3378
#1F3378
oklch(34.9% 0.121 267.5)
- #4A3700
#4A3700
oklch(34.8% 0.071 87)
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 #1F3378, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Marine Blue #01386A ΔE 0.036
- Twilight Blue #0A437A ΔE 0.045
- Marine #042E60 ΔE 0.052
- Prussian Blue #1D3557 ΔE 0.059
- Midnight Blue #191970 ΔE 0.066
- Cobalt #1E488F ΔE 0.067
- Dark Slate Blue #483D8B ΔE 0.076
- Royal #0C1793 ΔE 0.076
Use #1F3378 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.