#428DDB
Closest named color: Dark Sky Blue (#448EE4). oklch(63.2% 0.139 251.7), rgb(66, 141, 219).
Aa
Black text reads best on this color (6.06:1).
About this color
#428DDB is a medium-light, moderately saturated blue. In OKLCH its lightness is 63%, its chroma 0.139 and its hue 252°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.014 away. Black text reads best on it, at 6.06:1.
| Hue family | Blues |
| Lightness | medium-light (63%) |
| Chroma | moderately saturated (0.139) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 6.06:1 |
| White text | 3.46:1 |
Values
| HEX | #428DDB |
| RGB | rgb(66, 141, 219) |
| HSL | hsl(211, 68%, 56%) |
| OKLCH | oklch(63.2% 0.139 251.7) |
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 #428DDB | 3.46:1 | AA large text | Lc -67.3 | Content text, not long reading |
| Black text on #428DDB | 6.06:1 | AA | Lc 42.2 | Non-text elements, placeholder text |
| #428DDB text on white | 3.46:1 | AA large text | Lc 61.9 | Content text, not long reading |
| #428DDB text on black | 6.06:1 | AA | Lc -39.8 | Non-text elements, placeholder text |
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 500.
-
Step 50
50
#F1F6FC
oklch(97.1% 0.01 252.8)
-
Step 100
100
#E1EBF7
oklch(93.6% 0.019 252.9)
-
Step 200
200
#C8DBF2
oklch(88.4% 0.038 253.2)
-
Step 300
300
#A1C4EC
oklch(80.9% 0.068 252)
-
Step 400
400
#6CA5E3
oklch(70.8% 0.109 251.5)
-
Step 500
500 (this color)
#428DDB
oklch(63.2% 0.139 251.7)
-
Step 600
600
#1B75C8
oklch(55.6% 0.151 251.6)
-
Step 700
700
#0A62AD
oklch(49.2% 0.141 251.6)
-
Step 800
800
#0F508C
oklch(42.7% 0.117 251.7)
-
Step 900
900
#164370
oklch(37.7% 0.091 251.6)
-
Step 950
950
#0F2842
oklch(27.2% 0.058 251.5)
#428DDB 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) | #6A92DE | 0.043 |
| Deuteranopia (no green cones) | #5483D9 | 0.028 |
| Tritanopia (no blue cones) | #009FAA | 0.106 |
| Achromatopsia (no color) | #8A8A8A | 0.139 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #428DDB
#428DDB
oklch(63.2% 0.139 251.7)
- #BC7A00
#BC7A00
oklch(63.3% 0.136 71.8)
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 #428DDB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.014
- Chefchaouen Blue #4895EF ΔE 0.035
- Water Blue #0E87CC ΔE 0.040
- Soft Blue #6488EA ΔE 0.043
- Cornflower Blue #6495ED ΔE 0.048
- Cool Blue #4984B8 ΔE 0.054
- Dodger Blue #1E90FF ΔE 0.055
- Faded Blue #658CBB ΔE 0.056
Use #428DDB 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.