#284FAB
Closest named color: Cobalt (#1E488F). oklch(45.5% 0.154 263.9), rgb(40, 79, 171).
Aa
White text reads best on this color (7.50:1).
About this color
#284FAB is a medium-dark, vivid blue. In OKLCH its lightness is 45%, its chroma 0.154 and its hue 264°. Its hue sits on the cool side of the wheel. The nearest named color is Cobalt (#1E488F), ΔE 0.050 away. White text reads best on it, at 7.50:1.
| Hue family | Blues |
| Lightness | medium-dark (45%) |
| Chroma | vivid (0.154) |
| Temperature | cool |
| Nearest name | Cobalt (#1E488F) |
| Black text | 2.79:1 |
| White text | 7.50:1 |
Values
| HEX | #284FAB |
| RGB | rgb(40, 79, 171) |
| HSL | hsl(222, 62%, 41%) |
| OKLCH | oklch(45.5% 0.154 263.9) |
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 #284FAB | 7.50:1 | AAA | Lc -90.5 | Preferred for body text |
| Black text on #284FAB | 2.79:1 | Fails | Lc 18.4 | Dividers and decoration only |
| #284FAB text on white | 7.50:1 | AAA | Lc 85.6 | Fine for body text |
| #284FAB text on black | 2.79:1 | Fails | Lc -16.4 | 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
#F1F6FE
oklch(97.2% 0.012 259.8)
-
Step 100
100
#E1EAFC
oklch(93.6% 0.026 264.4)
-
Step 200
200
#C8DAFB
oklch(88.5% 0.05 262.6)
-
Step 300
300
#A3C1FC
oklch(81% 0.09 263.6)
-
Step 400
400
#729EFA
oklch(70.8% 0.144 263.8)
-
Step 500
500
#4E82F7
oklch(63.1% 0.184 263.9)
-
Step 600
600
#3368E6
oklch(55.6% 0.2 263.8)
-
Step 700
700
#2655C8
oklch(49% 0.187 263.9)
-
Step 800
800 (this color)
#284FAB
oklch(45.5% 0.154 263.9)
-
Step 900
900
#1F3C80
oklch(37.6% 0.12 264.1)
-
Step 950
950
#13244B
oklch(27% 0.076 264.2)
#284FAB 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) | #075BAE | 0.033 |
| Deuteranopia (no green cones) | #004FA9 | 0.022 |
| Tritanopia (no blue cones) | #006575 | 0.121 |
| Achromatopsia (no color) | #555555 | 0.154 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #284FAB
#284FAB
oklch(45.5% 0.154 263.9)
- #6F5100
#6F5100
oklch(45.5% 0.093 83.8)
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 #284FAB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cobalt #1E488F ΔE 0.050
- Dusk Blue #26538D ΔE 0.052
- Blue Blue #2242C7 ΔE 0.055
- Blueberry #464196 ΔE 0.055
- Sapphire #2138AB ΔE 0.058
- Denim Blue #3B5B92 ΔE 0.060
- Light Navy #155084 ΔE 0.067
- Twilight #4E518B ΔE 0.069
Use #284FAB 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.