#1F4579
Closest named color: Twilight Blue (#0A437A). oklch(39.1% 0.098 257), rgb(31, 69, 121).
Aa
White text reads best on this color (9.60:1).
About this color
#1F4579 is a dark, moderately saturated blue. In OKLCH its lightness is 39%, its chroma 0.098 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.016 away. White text reads best on it, at 9.60:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | moderately saturated (0.098) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.18:1 |
| White text | 9.60:1 |
Values
| HEX | #1F4579 |
| RGB | rgb(31, 69, 121) |
| HSL | hsl(215, 59%, 30%) |
| OKLCH | oklch(39.1% 0.098 257) |
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 #1F4579 | 9.60:1 | AAA | Lc -96.2 | Preferred for body text |
| Black text on #1F4579 | 2.18:1 | Fails | Lc 12.0 | Not readable |
| #1F4579 text on white | 9.60:1 | AAA | Lc 92.0 | Preferred for body text |
| #1F4579 text on black | 2.18:1 | Fails | Lc -10.4 | 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
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF8
oklch(93.6% 0.021 254.9)
-
Step 200
200
#C8DBF5
oklch(88.5% 0.041 256.2)
-
Step 300
300
#A2C3F1
oklch(80.9% 0.075 256.7)
-
Step 400
400
#70A2E9
oklch(70.6% 0.118 257.2)
-
Step 500
500
#4889E3
oklch(63.1% 0.152 257.1)
-
Step 600
600
#2871D1
oklch(55.6% 0.165 257)
-
Step 700
700
#1B5EB5
oklch(49.1% 0.153 257.1)
-
Step 800
800
#194D92
oklch(42.6% 0.126 257.1)
-
Step 900
900 (this color)
#1F4579
oklch(39.1% 0.098 257)
-
Step 950
950
#112644
oklch(26.9% 0.062 257.5)
#1F4579 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) | #2C497B | 0.020 |
| Deuteranopia (no green cones) | #1E4178 | 0.012 |
| Tritanopia (no blue cones) | #005159 | 0.077 |
| Achromatopsia (no color) | #454545 | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #1F4579
#1F4579
oklch(39.1% 0.098 257)
- #5E3E00
#5E3E00
oklch(39.1% 0.082 76)
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 #1F4579, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.016
- Light Navy #155084 ΔE 0.034
- Cobalt #1E488F ΔE 0.037
- Deep Sea Blue #015482 ΔE 0.044
- Dusk Blue #26538D ΔE 0.051
- Marine Blue #01386A ΔE 0.053
- Dark Grey Blue #29465B ΔE 0.053
- Dark Slate Blue #483D8B ΔE 0.066
Use #1F4579 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.