#428AC9
Closest named color: Cool Blue (#4984B8). oklch(61.6% 0.12 247.6), rgb(66, 138, 201).
Aa
Black text reads best on this color (5.71:1).
About this color
#428AC9 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 62%, its chroma 0.120 and its hue 248°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.027 away. Black text reads best on it, at 5.71:1.
| Hue family | Blues |
| Lightness | medium-dark (62%) |
| Chroma | moderately saturated (0.120) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.71:1 |
| White text | 3.67:1 |
Values
| HEX | #428AC9 |
| RGB | rgb(66, 138, 201) |
| HSL | hsl(208, 56%, 52%) |
| OKLCH | oklch(61.6% 0.12 247.6) |
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 #428AC9 | 3.67:1 | AA large text | Lc -69.6 | Content text, not long reading |
| Black text on #428AC9 | 5.71:1 | AA | Lc 40.0 | Non-text elements, placeholder text |
| #428AC9 text on white | 3.67:1 | AA large text | Lc 64.1 | Content text, not long reading |
| #428AC9 text on black | 5.71:1 | AA | Lc -37.6 | 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
#F1F6FB
oklch(97.1% 0.009 247.9)
-
Step 100
100
#E1EBF5
oklch(93.5% 0.017 248)
-
Step 200
200
#C9DCEE
oklch(88.6% 0.032 246.7)
-
Step 300
300
#A3C5E5
oklch(80.9% 0.058 247)
-
Step 400
400
#70A6D8
oklch(70.7% 0.093 247.4)
-
Step 500
500 (this color)
#428AC9
oklch(61.6% 0.12 247.6)
-
Step 600
600
#2478BB
oklch(55.7% 0.13 247.4)
-
Step 700
700
#1464A1
oklch(49% 0.121 247.6)
-
Step 800
800
#155283
oklch(42.7% 0.101 247.8)
-
Step 900
900
#1A4469
oklch(37.6% 0.079 248.2)
-
Step 950
950
#10283D
oklch(26.9% 0.05 247.3)
#428AC9 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) | #6E8CCC | 0.046 |
| Deuteranopia (no green cones) | #5B7FC8 | 0.035 |
| Tritanopia (no blue cones) | #0099A0 | 0.091 |
| Achromatopsia (no color) | #858585 | 0.120 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #428AC9
#428AC9
oklch(61.6% 0.12 247.6)
- #B47526
#B47526
oklch(61.6% 0.12 67.4)
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 #428AC9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.027
- Water Blue #0E87CC ΔE 0.029
- Steel Blue #4682B4 ΔE 0.035
- Faded Blue #658CBB ΔE 0.041
- Dark Sky Blue #448EE4 ΔE 0.041
- Off Blue #5684AE ΔE 0.042
- Dusty Blue #5A86AD ΔE 0.045
- Blue NCS #118AB2 ΔE 0.047
Use #428AC9 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.