#1F3C7D
Closest named color: Twilight Blue (#0A437A). oklch(37.3% 0.116 263.7), rgb(31, 60, 125).
Aa
White text reads best on this color (10.49:1).
About this color
#1F3C7D is a dark, moderately saturated blue. In OKLCH its lightness is 37%, its chroma 0.116 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.024 away. White text reads best on it, at 10.49:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.116) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.00:1 |
| White text | 10.49:1 |
Values
| HEX | #1F3C7D |
| RGB | rgb(31, 60, 125) |
| HSL | hsl(221, 60%, 31%) |
| OKLCH | oklch(37.3% 0.116 263.7) |
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 #1F3C7D | 10.49:1 | AAA | Lc -98.0 | Preferred for body text |
| Black text on #1F3C7D | 2.00:1 | Fails | Lc 9.9 | Not readable |
| #1F3C7D text on white | 10.49:1 | AAA | Lc 94.0 | Preferred for body text |
| #1F3C7D text on black | 2.00:1 | Fails | Lc -8.5 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E1EAFB
oklch(93.5% 0.025 263.3)
-
Step 200
200
#C9DAFA
oklch(88.6% 0.048 263.1)
-
Step 300
300
#A4C1FA
oklch(81% 0.087 263.6)
-
Step 400
400
#739EF7
oklch(70.7% 0.139 263.7)
-
Step 500
500
#4F83F4
oklch(63.1% 0.178 263.5)
-
Step 600
600
#3569E2
oklch(55.6% 0.193 263.7)
-
Step 700
700
#2857C5
oklch(49.2% 0.18 263.6)
-
Step 800
800
#22489F
oklch(42.8% 0.148 263.6)
-
Step 900
900 (this color)
#1F3C7D
oklch(37.3% 0.116 263.7)
-
Step 950
950
#13244A
oklch(26.9% 0.074 264)
#1F3C7D 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) | #15447F | 0.023 |
| Deuteranopia (no green cones) | #003B7C | 0.021 |
| Tritanopia (no blue cones) | #004B56 | 0.092 |
| Achromatopsia (no color) | #3F3F3F | 0.116 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F3C7D
#1F3C7D
oklch(37.3% 0.116 263.7)
- #543C00
#543C00
oklch(37.3% 0.077 83.1)
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 #1F3C7D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.024
- Marine Blue #01386A ΔE 0.042
- Cobalt #1E488F ΔE 0.043
- Light Navy #155084 ΔE 0.057
- Dark Slate Blue #483D8B ΔE 0.063
- Prussian Blue #1D3557 ΔE 0.067
- Deep Sea Blue #015482 ΔE 0.069
- Marine #042E60 ΔE 0.070
Use #1F3C7D 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.