#1F3C77
Closest named color: Twilight Blue (#0A437A). oklch(36.9% 0.107 262.6), rgb(31, 60, 119).
Aa
White text reads best on this color (10.65:1).
About this color
#1F3C77 is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.107 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.022 away. White text reads best on it, at 10.65:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.107) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.97:1 |
| White text | 10.65:1 |
Values
| HEX | #1F3C77 |
| RGB | rgb(31, 60, 119) |
| HSL | hsl(220, 59%, 29%) |
| OKLCH | oklch(36.9% 0.107 262.6) |
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 #1F3C77 | 10.65:1 | AAA | Lc -98.4 | Preferred for body text |
| Black text on #1F3C77 | 1.97:1 | Fails | Lc 9.5 | Not readable |
| #1F3C77 text on white | 10.65:1 | AAA | Lc 94.4 | Preferred for body text |
| #1F3C77 text on black | 1.97:1 | Fails | Lc -8.2 | 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
#CADAF7
oklch(88.5% 0.044 262.4)
-
Step 300
300
#A5C1F5
oklch(80.9% 0.08 262.6)
-
Step 400
400
#759FF0
oklch(70.6% 0.128 262.7)
-
Step 500
500
#5285EB
oklch(63.1% 0.163 262.6)
-
Step 600
600
#376CDA
oklch(55.7% 0.178 262.7)
-
Step 700
700
#2959BD
oklch(49% 0.166 262.6)
-
Step 800
800
#234A99
oklch(42.8% 0.137 262.4)
-
Step 900
900 (this color)
#1F3C77
oklch(36.9% 0.107 262.6)
-
Step 950
950
#142547
oklch(27% 0.067 262.7)
#1F3C77 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) | #1C4379 | 0.020 |
| Deuteranopia (no green cones) | #063A76 | 0.020 |
| Tritanopia (no blue cones) | #004A53 | 0.087 |
| Achromatopsia (no color) | #3E3E3E | 0.107 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F3C77
#1F3C77
oklch(36.9% 0.107 262.6)
- #533B00
#533B00
oklch(36.9% 0.076 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 #1F3C77, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.022
- Marine Blue #01386A ΔE 0.035
- Cobalt #1E488F ΔE 0.050
- Prussian Blue #1D3557 ΔE 0.057
- Light Navy #155084 ΔE 0.059
- Marine #042E60 ΔE 0.063
- Dark Grey Blue #29465B ΔE 0.064
- Dark Slate Blue #483D8B ΔE 0.068
Use #1F3C77 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.