#428EBC
Closest named color: Cool Blue (#4984B8). oklch(61.8% 0.102 238.1), rgb(66, 142, 188).
Aa
Black text reads best on this color (5.82:1).
About this color
#428EBC is a medium-dark, moderately saturated blue. In OKLCH its lightness is 62%, its chroma 0.102 and its hue 238°. 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 5.82:1.
| Hue family | Blues |
| Lightness | medium-dark (62%) |
| Chroma | moderately saturated (0.102) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.82:1 |
| White text | 3.60:1 |
Values
| HEX | #428EBC |
| RGB | rgb(66, 142, 188) |
| HSL | hsl(203, 48%, 50%) |
| OKLCH | oklch(61.8% 0.102 238.1) |
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 #428EBC | 3.60:1 | AA large text | Lc -68.9 | Content text, not long reading |
| Black text on #428EBC | 5.82:1 | AA | Lc 40.7 | Non-text elements, placeholder text |
| #428EBC text on white | 3.60:1 | AA large text | Lc 63.4 | Content text, not long reading |
| #428EBC text on black | 5.82:1 | AA | Lc -38.3 | 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
#F1F6F9
oklch(97% 0.007 233.6)
-
Step 100
100
#E1EBF3
oklch(93.5% 0.015 241.8)
-
Step 200
200
#C9DCEA
oklch(88.5% 0.028 239.7)
-
Step 300
300
#A3C6DE
oklch(80.9% 0.051 238.2)
-
Step 400
400
#70A8CD
oklch(70.7% 0.08 238.4)
-
Step 500
500 (this color)
#428EBC
oklch(61.8% 0.102 238.1)
-
Step 600
600
#217BAC
oklch(55.5% 0.111 238.2)
-
Step 700
700
#116894
oklch(49.2% 0.103 237.9)
-
Step 800
800
#135578
oklch(42.7% 0.085 237.7)
-
Step 900
900
#194661
oklch(37.7% 0.067 238.6)
-
Step 950
950
#102939
oklch(26.9% 0.043 239.2)
#428EBC 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) | #798EBE | 0.058 |
| Deuteranopia (no green cones) | #6881BB | 0.049 |
| Tritanopia (no blue cones) | #009A9E | 0.072 |
| Achromatopsia (no color) | #878787 | 0.102 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #428EBC
#428EBC
oklch(61.8% 0.102 238.1)
- #B37543
#B37543
oklch(61.7% 0.102 58.2)
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 #428EBC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.027
- Dusty Blue #5A86AD ΔE 0.032
- Off Blue #5684AE ΔE 0.033
- Faded Blue #658CBB ΔE 0.033
- Steel Blue #4682B4 ΔE 0.033
- Blue NCS #118AB2 ΔE 0.034
- Water Blue #0E87CC ΔE 0.044
- Teal Blue #01889F ΔE 0.058
Use #428EBC 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.