#284B8B
Closest named color: Cobalt (#1E488F). oklch(42.2% 0.114 261.3), rgb(40, 75, 139).
Aa
White text reads best on this color (8.50:1).
About this color
#284B8B is a dark, moderately saturated blue. In OKLCH its lightness is 42%, its chroma 0.114 and its hue 261°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.015 away. White text reads best on it, at 8.50:1.
| Hue family | Blues |
| Lightness | dark (42%) |
| Chroma | moderately saturated (0.114) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.46:1 |
| White text | 8.50:1 |
Values
| HEX | #284B8B |
| RGB | rgb(40, 75, 139) |
| HSL | hsl(219, 55%, 35%) |
| OKLCH | oklch(42.2% 0.114 261.3) |
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 #284B8B | 8.50:1 | AAA | Lc -93.5 | Preferred for body text |
| Black text on #284B8B | 2.46:1 | Fails | Lc 15.0 | Dividers and decoration only |
| #284B8B text on white | 8.50:1 | AAA | Lc 89.0 | Fine for body text |
| #284B8B text on black | 2.46:1 | Fails | Lc -13.2 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E3EAF7
oklch(93.6% 0.019 263)
-
Step 200
200
#CCDAF2
oklch(88.5% 0.036 261.3)
-
Step 300
300
#A9C2EC
oklch(81% 0.066 260.7)
-
Step 400
400
#7BA1E3
oklch(70.8% 0.106 261.1)
-
Step 500
500
#5988DB
oklch(63.1% 0.136 261)
-
Step 600
600
#3F70C9
oklch(55.7% 0.148 261.3)
-
Step 700
700
#315DAE
oklch(49.1% 0.138 261.4)
-
Step 800
800 (this color)
#284B8B
oklch(42.2% 0.114 261.3)
-
Step 900
900
#264070
oklch(37.7% 0.089 261.6)
-
Step 950
950
#162642
oklch(27% 0.057 260.9)
#284B8B 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) | #2B528D | 0.021 |
| Deuteranopia (no green cones) | #19488A | 0.017 |
| Tritanopia (no blue cones) | #005A64 | 0.092 |
| Achromatopsia (no color) | #4D4D4D | 0.114 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #284B8B
#284B8B
oklch(42.2% 0.114 261.3)
- #654800
#654800
oklch(42.2% 0.087 82.1)
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 #284B8B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.015
- Dusk Blue #26538D ΔE 0.023
- Light Navy #155084 ΔE 0.024
- Deep Sea Blue #015482 ΔE 0.038
- Twilight Blue #0A437A ΔE 0.045
- Light Navy Blue #2E5A88 ΔE 0.047
- Blueberry #464196 ΔE 0.049
- Dark Slate Blue #483D8B ΔE 0.053
Use #284B8B 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.