#284F8B
Closest named color: Dusk Blue (#26538D). oklch(43.1% 0.109 258.8), rgb(40, 79, 139).
Aa
White text reads best on this color (8.13:1).
About this color
#284F8B is a dark, moderately saturated blue. In OKLCH its lightness is 43%, its chroma 0.109 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk Blue (#26538D), ΔE 0.011 away. White text reads best on it, at 8.13:1.
| Hue family | Blues |
| Lightness | dark (43%) |
| Chroma | moderately saturated (0.109) |
| Temperature | cool |
| Nearest name | Dusk Blue (#26538D) |
| Black text | 2.58:1 |
| White text | 8.13:1 |
Values
| HEX | #284F8B |
| RGB | rgb(40, 79, 139) |
| HSL | hsl(216, 55%, 35%) |
| OKLCH | oklch(43.1% 0.109 258.8) |
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 #284F8B | 8.13:1 | AAA | Lc -92.5 | Preferred for body text |
| Black text on #284F8B | 2.58:1 | Fails | Lc 16.1 | Dividers and decoration only |
| #284F8B text on white | 8.13:1 | AAA | Lc 87.9 | Fine for body text |
| #284F8B text on black | 2.58:1 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E3EAF7
oklch(93.6% 0.019 263)
-
Step 200
200
#CBDAF1
oklch(88.4% 0.036 258.9)
-
Step 300
300
#A8C2EA
oklch(80.8% 0.064 258.9)
-
Step 400
400
#79A2E0
oklch(70.7% 0.102 258.5)
-
Step 500
500
#5789D7
oklch(63% 0.13 259)
-
Step 600
600
#3C72C5
oklch(55.7% 0.141 258.8)
-
Step 700
700
#2E5FAA
oklch(49.2% 0.131 258.8)
-
Step 800
800 (this color)
#284F8B
oklch(43.1% 0.109 258.8)
-
Step 900
900
#24416E
oklch(37.7% 0.085 258.9)
-
Step 950
950
#162640
oklch(26.9% 0.053 259.7)
#284F8B 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) | #33548D | 0.020 |
| Deuteranopia (no green cones) | #224B8A | 0.014 |
| Tritanopia (no blue cones) | #005D66 | 0.087 |
| Achromatopsia (no color) | #4F4F4F | 0.109 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #284F8B
#284F8B
oklch(43.1% 0.109 258.8)
- #6A4900
#6A4900
oklch(43.1% 0.089 79)
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 #284F8B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk Blue #26538D ΔE 0.011
- Light Navy #155084 ΔE 0.020
- Cobalt #1E488F ΔE 0.025
- Deep Sea Blue #015482 ΔE 0.031
- Light Navy Blue #2E5A88 ΔE 0.036
- Denim Blue #3B5B92 ΔE 0.044
- Twilight #4E518B ΔE 0.049
- Twilight Blue #0A437A ΔE 0.052
Use #284F8B 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.