#18428B
Closest named color: Cobalt (#1E488F). oklch(39.5% 0.13 260.6), rgb(24, 66, 139).
Aa
White text reads best on this color (9.58:1).
About this color
#18428B is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.130 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.019 away. White text reads best on it, at 9.58:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.130) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.19:1 |
| White text | 9.58:1 |
Values
| HEX | #18428B |
| RGB | rgb(24, 66, 139) |
| HSL | hsl(218, 71%, 32%) |
| OKLCH | oklch(39.5% 0.13 260.6) |
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 #18428B | 9.58:1 | AAA | Lc -96.0 | Preferred for body text |
| Black text on #18428B | 2.19:1 | Fails | Lc 12.2 | Not readable |
| #18428B text on white | 9.58:1 | AAA | Lc 91.7 | Preferred for body text |
| #18428B text on black | 2.19:1 | Fails | Lc -10.7 | 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
#F0F6FF
oklch(97.1% 0.014 258.3)
-
Step 100
100
#DFEBFD
oklch(93.6% 0.028 258.4)
-
Step 200
200
#C5DAFE
oklch(88.4% 0.055 261.2)
-
Step 300
300
#9DC2FF
oklch(81% 0.096 260.2)
-
Step 400
400
#679FFF
oklch(70.7% 0.153 260.6)
-
Step 500
500
#3B83FF
oklch(63.1% 0.198 260.5)
-
Step 600
600
#1668EF
oklch(55.6% 0.217 260.6)
-
Step 700
700
#0655D0
oklch(49% 0.202 260.7)
-
Step 800
800
#0B47A8
oklch(42.7% 0.167 260.5)
-
Step 900
900 (this color)
#18428B
oklch(39.5% 0.13 260.6)
-
Step 950
950
#0C244E
oklch(26.9% 0.083 260.7)
#18428B 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) | #124B8E | 0.025 |
| Deuteranopia (no green cones) | #00408A | 0.015 |
| Tritanopia (no blue cones) | #005460 | 0.101 |
| Achromatopsia (no color) | #454545 | 0.131 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #18428B
#18428B
oklch(39.5% 0.13 260.6)
- #5D4100
#5D4100
oklch(39.6% 0.082 80.8)
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 #18428B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.019
- Twilight Blue #0A437A ΔE 0.031
- Light Navy #155084 ΔE 0.044
- Dusk Blue #26538D ΔE 0.052
- Deep Sea Blue #015482 ΔE 0.056
- Sapphire #2138AB ΔE 0.058
- Blueberry #464196 ΔE 0.059
- Dark Slate Blue #483D8B ΔE 0.060
Use #18428B 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.