#1F3B77
Closest named color: Twilight Blue (#0A437A). oklch(36.6% 0.108 263.3), rgb(31, 59, 119).
Aa
White text reads best on this color (10.76:1).
About this color
#1F3B77 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.108 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.025 away. White text reads best on it, at 10.76:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.108) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.95:1 |
| White text | 10.76:1 |
Values
| HEX | #1F3B77 |
| RGB | rgb(31, 59, 119) |
| HSL | hsl(221, 59%, 29%) |
| OKLCH | oklch(36.6% 0.108 263.3) |
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 #1F3B77 | 10.76:1 | AAA | Lc -98.6 | Preferred for body text |
| Black text on #1F3B77 | 1.95:1 | Fails | Lc 9.3 | Not readable |
| #1F3B77 text on white | 10.76:1 | AAA | Lc 94.6 | Preferred for body text |
| #1F3B77 text on black | 1.95:1 | Fails | Lc -8.0 | 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
#F2F6FD
oklch(97.2% 0.01 261.8)
-
Step 100
100
#E2EAFA
oklch(93.6% 0.023 264.5)
-
Step 200
200
#CADAF8
oklch(88.6% 0.045 263.1)
-
Step 300
300
#A5C1F6
oklch(80.9% 0.081 263)
-
Step 400
400
#759FF2
oklch(70.7% 0.131 263.1)
-
Step 500
500
#5284ED
oklch(63% 0.167 263.3)
-
Step 600
600
#386BDB
oklch(55.6% 0.18 263.3)
-
Step 700
700
#2B59BE
oklch(49.2% 0.167 263.2)
-
Step 800
800
#24499A
oklch(42.7% 0.139 263.3)
-
Step 900
900 (this color)
#1F3B77
oklch(36.6% 0.108 263.3)
-
Step 950
950
#142548
oklch(27.1% 0.069 263.1)
#1F3B77 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) | #1A4279 | 0.020 |
| Deuteranopia (no green cones) | #023A76 | 0.021 |
| Tritanopia (no blue cones) | #004953 | 0.087 |
| Achromatopsia (no color) | #3E3E3E | 0.108 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F3B77
#1F3B77
oklch(36.6% 0.108 263.3)
- #523A00
#523A00
oklch(36.6% 0.075 82.4)
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 #1F3B77, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.025
- Marine Blue #01386A ΔE 0.034
- Cobalt #1E488F ΔE 0.052
- Prussian Blue #1D3557 ΔE 0.057
- Marine #042E60 ΔE 0.061
- Light Navy #155084 ΔE 0.062
- Dark Grey Blue #29465B ΔE 0.066
- Dark Slate Blue #483D8B ΔE 0.069
Use #1F3B77 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.