#04397F
Closest named color: Twilight Blue (#0A437A). oklch(36% 0.129 258.2), rgb(4, 57, 127).
Aa
White text reads best on this color (11.07:1).
About this color
#04397F is a dark, moderately saturated blue. In OKLCH its lightness is 36%, its chroma 0.129 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.032 away. White text reads best on it, at 11.07:1.
| Hue family | Blues |
| Lightness | dark (36%) |
| Chroma | moderately saturated (0.129) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.89:1 |
| White text | 11.07:1 |
Values
| HEX | #04397F |
| RGB | rgb(4, 57, 127) |
| HSL | hsl(214, 94%, 26%) |
| OKLCH | oklch(36% 0.129 258.2) |
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 #04397F | 11.07:1 | AAA | Lc -98.8 | Preferred for body text |
| Black text on #04397F | 1.89:1 | Fails | Lc 9.0 | Not readable |
| #04397F text on white | 11.07:1 | AAA | Lc 94.9 | Preferred for body text |
| #04397F text on black | 1.89:1 | Fails | Lc -7.7 | 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
#F0F6FE
oklch(97.1% 0.012 255.5)
-
Step 100
100
#DFEBFD
oklch(93.6% 0.028 258.4)
-
Step 200
200
#C4DBFD
oklch(88.5% 0.053 258)
-
Step 300
300
#9AC3FF
oklch(81% 0.096 257.8)
-
Step 400
400
#61A0FF
oklch(70.6% 0.154 258.4)
-
Step 500
500
#2F85FE
oklch(63.1% 0.198 258.1)
-
Step 600
600
#006BE9
oklch(55.5% 0.208 258.3)
-
Step 700
700
#005AC6
oklch(49.1% 0.184 258.2)
-
Step 800
800
#0049A4
oklch(42.7% 0.16 258.3)
-
Step 900
900 (this color)
#04397F
oklch(36% 0.129 258.2)
-
Step 950
950
#09254D
oklch(27% 0.081 258.1)
#04397F 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) | #004181 | 0.023 |
| Deuteranopia (no green cones) | #00377E | 0.007 |
| Tritanopia (no blue cones) | #004A56 | 0.097 |
| Achromatopsia (no color) | #3C3C3C | 0.129 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #04397F
#04397F
oklch(36% 0.129 258.2)
- #523700
#523700
oklch(35.9% 0.075 78.1)
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 #04397F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.032
- Marine Blue #01386A ΔE 0.036
- Cobalt #1E488F ΔE 0.055
- Marine #042E60 ΔE 0.061
- Prussian Blue #1D3557 ΔE 0.070
- Light Navy #155084 ΔE 0.070
- Royal #0C1793 ΔE 0.076
- Sapphire #2138AB ΔE 0.077
Use #04397F 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.