#284FA4
Closest named color: Cobalt (#1E488F). oklch(44.9% 0.145 263.2), rgb(40, 79, 164).
Aa
White text reads best on this color (7.65:1).
About this color
#284FA4 is a dark, vivid blue. In OKLCH its lightness is 45%, its chroma 0.145 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.040 away. White text reads best on it, at 7.65:1.
| Hue family | Blues |
| Lightness | dark (45%) |
| Chroma | vivid (0.145) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.74:1 |
| White text | 7.65:1 |
Values
| HEX | #284FA4 |
| RGB | rgb(40, 79, 164) |
| HSL | hsl(221, 61%, 40%) |
| OKLCH | oklch(44.9% 0.145 263.2) |
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 #284FA4 | 7.65:1 | AAA | Lc -91.0 | Preferred for body text |
| Black text on #284FA4 | 2.74:1 | Fails | Lc 17.9 | Dividers and decoration only |
| #284FA4 text on white | 7.65:1 | AAA | Lc 86.2 | Fine for body text |
| #284FA4 text on black | 2.74:1 | Fails | Lc -15.9 | Dividers and decoration only |
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
#F1F6FD
oklch(97.1% 0.011 256.7)
-
Step 100
100
#E1EAFB
oklch(93.5% 0.025 263.3)
-
Step 200
200
#C9DAF9
oklch(88.5% 0.047 262.5)
-
Step 300
300
#A4C1F8
oklch(80.9% 0.084 263)
-
Step 400
400
#749FF5
oklch(70.8% 0.135 263.2)
-
Step 500
500
#5084F1
oklch(63.2% 0.173 263.2)
-
Step 600
600
#356ADF
oklch(55.5% 0.188 263.3)
-
Step 700
700
#2858C2
oklch(49.2% 0.174 263.1)
-
Step 800
800 (this color)
#284FA4
oklch(44.9% 0.145 263.2)
-
Step 900
900
#203E7D
oklch(37.8% 0.113 263)
-
Step 950
950
#132549
oklch(27.1% 0.071 262.6)
#284FA4 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) | #1959A7 | 0.027 |
| Deuteranopia (no green cones) | #004EA2 | 0.023 |
| Tritanopia (no blue cones) | #006372 | 0.113 |
| Achromatopsia (no color) | #535353 | 0.145 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #284FA4
#284FA4
oklch(44.9% 0.145 263.2)
- #6E4F00
#6E4F00
oklch(44.9% 0.092 82.4)
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 #284FA4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.040
- Dusk Blue #26538D ΔE 0.041
- Blueberry #464196 ΔE 0.050
- Denim Blue #3B5B92 ΔE 0.053
- Light Navy #155084 ΔE 0.056
- Sapphire #2138AB ΔE 0.059
- Light Navy Blue #2E5A88 ΔE 0.060
- Twilight #4E518B ΔE 0.062
Use #284FA4 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.