#04398B
Closest named color: Twilight Blue (#0A437A). oklch(37% 0.146 260.1), rgb(4, 57, 139).
Aa
White text reads best on this color (10.69:1).
About this color
#04398B is a dark, vivid blue. In OKLCH its lightness is 37%, its chroma 0.146 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Twilight Blue (#0A437A), ΔE 0.042 away. White text reads best on it, at 10.69:1.
| Hue family | Blues |
| Lightness | dark (37%) |
| Chroma | vivid (0.146) |
| Temperature | cool |
| Nearest name | Twilight Blue (#0A437A) |
| Black text | 1.96:1 |
| White text | 10.69:1 |
Values
| HEX | #04398B |
| RGB | rgb(4, 57, 139) |
| HSL | hsl(216, 94%, 28%) |
| OKLCH | oklch(37% 0.146 260.1) |
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 #04398B | 10.69:1 | AAA | Lc -98.1 | Preferred for body text |
| Black text on #04398B | 1.96:1 | Fails | Lc 9.9 | Not readable |
| #04398B text on white | 10.69:1 | AAA | Lc 94.0 | Preferred for body text |
| #04398B text on black | 1.96:1 | 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
#F0F6FF
oklch(97.1% 0.014 258.3)
-
Step 100
100
#DEEBFF
oklch(93.6% 0.031 258.9)
-
Step 200
200
#C4DAFF
oklch(88.4% 0.057 260.8)
-
Step 300
300
#9DC2FF
oklch(81% 0.096 260.2)
-
Step 400
400
#669FFF
oklch(70.7% 0.154 260.3)
-
Step 500
500
#3983FF
oklch(63.1% 0.199 260.2)
-
Step 600
600
#0067F5
oklch(55.7% 0.227 260)
-
Step 700
700
#0056D0
oklch(49.2% 0.201 260.1)
-
Step 800
800
#0046AC
oklch(42.7% 0.175 260)
-
Step 900
900 (this color)
#04398B
oklch(37% 0.146 260.1)
-
Step 950
950
#072353
oklch(26.9% 0.094 260.5)
#04398B 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) | #00448E | 0.030 |
| Deuteranopia (no green cones) | #003889 | 0.005 |
| Tritanopia (no blue cones) | #004E5C | 0.111 |
| Achromatopsia (no color) | #3E3E3E | 0.146 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #04398B
#04398B
oklch(37% 0.146 260.1)
- #553A00
#553A00
oklch(37% 0.077 79.3)
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 #04398B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Twilight Blue #0A437A ΔE 0.042
- Cobalt #1E488F ΔE 0.048
- Marine Blue #01386A ΔE 0.057
- Sapphire #2138AB ΔE 0.057
- Royal #0C1793 ΔE 0.069
- Light Navy #155084 ΔE 0.070
- Dark Slate Blue #483D8B ΔE 0.078
- Blueberry #464196 ΔE 0.079
Use #04398B 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.