#284B9B
Closest named color: Cobalt (#1E488F). oklch(43.4% 0.137 263.8), rgb(40, 75, 155).
Aa
White text reads best on this color (8.17:1).
About this color
#284B9B is a dark, moderately saturated blue. In OKLCH its lightness is 43%, its chroma 0.137 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.024 away. White text reads best on it, at 8.17:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.137) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.56:1 |
| White text | 8.17:1 |
Values
| HEX | #284B9B |
| RGB | rgb(40, 75, 155) |
| HSL | hsl(222, 59%, 38%) |
| OKLCH | oklch(43.4% 0.137 263.8) |
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 #284B9B | 8.17:1 | AAA | Lc -92.5 | Preferred for body text |
| Black text on #284B9B | 2.56:1 | Fails | Lc 16.1 | Dividers and decoration only |
| #284B9B text on white | 8.17:1 | AAA | Lc 87.9 | Fine for body text |
| #284B9B text on black | 2.56:1 | Fails | Lc -14.3 | 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 800.
-
Step 50
50
#F2F6FD
oklch(97.2% 0.01 261.8)
-
Step 100
100
#E2EAFA
oklch(93.6% 0.023 264.5)
-
Step 200
200
#CADAF7
oklch(88.5% 0.044 262.4)
-
Step 300
300
#A6C1F5
oklch(80.9% 0.08 263.3)
-
Step 400
400
#779FF0
oklch(70.7% 0.127 263.5)
-
Step 500
500
#5584EB
oklch(63.1% 0.163 263.9)
-
Step 600
600
#3B6BDA
oklch(55.6% 0.178 263.9)
-
Step 700
700
#2D59BD
oklch(49.2% 0.165 263.6)
-
Step 800
800 (this color)
#284B9B
oklch(43.4% 0.137 263.8)
-
Step 900
900
#233E7A
oklch(37.7% 0.107 263.8)
-
Step 950
950
#152547
oklch(27.1% 0.067 263.6)
#284B9B 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) | #1A559E | 0.027 |
| Deuteranopia (no green cones) | #004A99 | 0.025 |
| Tritanopia (no blue cones) | #005E6B | 0.110 |
| Achromatopsia (no color) | #4F4F4F | 0.137 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #284B9B
#284B9B
oklch(43.4% 0.137 263.8)
- #684C00
#684C00
oklch(43.5% 0.089 84.2)
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 #284B9B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.024
- Dusk Blue #26538D ΔE 0.034
- Blueberry #464196 ΔE 0.043
- Light Navy #155084 ΔE 0.045
- Dark Slate Blue #483D8B ΔE 0.055
- Sapphire #2138AB ΔE 0.055
- Deep Sea Blue #015482 ΔE 0.056
- Denim Blue #3B5B92 ΔE 0.056
Use #284B9B 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.