#428FB9
Closest named color: Cool Blue (#4984B8). oklch(61.9% 0.099 235.4), rgb(66, 143, 185).
Aa
Black text reads best on this color (5.86:1).
About this color
#428FB9 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 62%, its chroma 0.099 and its hue 235°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.031 away. Black text reads best on it, at 5.86:1.
| Hue family | Blues |
| Lightness | medium-dark (62%) |
| Chroma | moderately saturated (0.099) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.86:1 |
| White text | 3.58:1 |
Values
| HEX | #428FB9 |
| RGB | rgb(66, 143, 185) |
| HSL | hsl(201, 47%, 49%) |
| OKLCH | oklch(61.9% 0.099 235.4) |
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 #428FB9 | 3.58:1 | AA large text | Lc -68.7 | Content text, not long reading |
| Black text on #428FB9 | 5.86:1 | AA | Lc 40.9 | Non-text elements, placeholder text |
| #428FB9 text on white | 3.58:1 | AA large text | Lc 63.2 | Content text, not long reading |
| #428FB9 text on black | 5.86:1 | AA | Lc -38.5 | 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
#E1ECF2
oklch(93.7% 0.014 231.2)
-
Step 200
200
#C9DCE9
oklch(88.4% 0.027 237.6)
-
Step 300
300
#A3C6DC
oklch(80.8% 0.049 235.8)
-
Step 400
400
#70A9CA
oklch(70.8% 0.077 234.8)
-
Step 500
500 (this color)
#428FB9
oklch(61.9% 0.099 235.4)
-
Step 600
600
#207CA9
oklch(55.6% 0.107 235.5)
-
Step 700
700
#0F6991
oklch(49.2% 0.099 234.9)
-
Step 800
800
#135576
oklch(42.6% 0.083 236.1)
-
Step 900
900
#19475F
oklch(37.8% 0.064 235)
-
Step 950
950
#102938
oklch(26.9% 0.042 237.4)
#428FB9 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) | #7B8EBB | 0.061 |
| Deuteranopia (no green cones) | #6B82B8 | 0.051 |
| Tritanopia (no blue cones) | #009A9D | 0.067 |
| Achromatopsia (no color) | #878787 | 0.099 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #428FB9
#428FB9
oklch(61.9% 0.099 235.4)
- #B37549
#B37549
oklch(61.8% 0.098 55.2)
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 #428FB9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.031
- Dusty Blue #5A86AD ΔE 0.031
- Blue NCS #118AB2 ΔE 0.033
- Off Blue #5684AE ΔE 0.033
- Faded Blue #658CBB ΔE 0.034
- Steel Blue #4682B4 ΔE 0.036
- Water Blue #0E87CC ΔE 0.049
- Teal Blue #01889F ΔE 0.055
Use #428FB9 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.