#004571
Closest named color: Twilight Blue (#0A437A). oklch(37.8% 0.096 245.5), rgb(0, 69, 113).
Aa
White text reads best on this color (10.04:1).
About this color
#004571 is a dark, moderately saturated blue. In OKLCH its lightness is 38%, its chroma 0.096 and its hue 245°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.018 away. White text reads best on it, at 10.04:1.
| Hue family | Blues |
| Lightness | dark (38%) |
| Chroma | moderately saturated (0.096) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 2.08:1 |
| White text | 10.04:1 |
Values
| HEX | #004571 |
| RGB | rgb(0, 69, 113) |
| HSL | hsl(203, 100%, 22%) |
| OKLCH | oklch(37.8% 0.096 245.5) |
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 #004571 | 10.04:1 | AAA | Lc -96.9 | Preferred for body text |
| Black text on #004571 | 2.08:1 | Fails | Lc 11.2 | Not readable |
| #004571 text on white | 10.04:1 | AAA | Lc 92.8 | Preferred for body text |
| #004571 text on black | 2.08:1 | Fails | Lc -9.7 | 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
#F0F6FC
oklch(97% 0.01 247.9)
-
Step 100
100
#DFECF7
oklch(93.7% 0.02 243.4)
-
Step 200
200
#C4DDF3
oklch(88.6% 0.04 244.8)
-
Step 300
300
#9AC6ED
oklch(80.9% 0.072 245.6)
-
Step 400
400
#5EA7E4
oklch(70.6% 0.116 245.7)
-
Step 500
500
#2490DC
oklch(63.2% 0.147 245.4)
-
Step 600
600
#0079C0
oklch(55.7% 0.141 245.3)
-
Step 700
700
#0065A2
oklch(49% 0.125 245.5)
-
Step 800
800
#005386
oklch(42.8% 0.108 245.3)
-
Step 900
900 (this color)
#004571
oklch(37.8% 0.096 245.5)
-
Step 950
950
#062942
oklch(27.1% 0.061 244.7)
#004571 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) | #2F4773 | 0.037 |
| Deuteranopia (no green cones) | #1F3E70 | 0.025 |
| Tritanopia (no blue cones) | #005055 | 0.068 |
| Achromatopsia (no color) | #424242 | 0.096 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #004571
#004571
oklch(37.8% 0.096 245.5)
- #603700
#603700
oklch(37.9% 0.085 65.4)
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 #004571, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.018
- Marine Blue #01386A ΔE 0.041
- Light Navy #155084 ΔE 0.046
- Dark Grey Blue #29465B ΔE 0.046
- Deep Sea Blue #015482 ΔE 0.051
- Cobalt #1E488F ΔE 0.055
- Charcoal #264653 ΔE 0.057
- Prussian Blue #1D3557 ΔE 0.060
Use #004571 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.