#427ACC
Closest named color: Windows Blue (#3778BF). oklch(58.2% 0.14 258), rgb(66, 122, 204).
Aa
Black text reads best on this color (4.88:1).
About this color
#427ACC is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.140 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.023 away. Black text reads best on it, at 4.88:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.140) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.88:1 |
| White text | 4.29:1 |
Values
| HEX | #427ACC |
| RGB | rgb(66, 122, 204) |
| HSL | hsl(216, 58%, 53%) |
| OKLCH | oklch(58.2% 0.14 258) |
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 #427ACC | 4.29:1 | AA large text | Lc -74.9 | Content text, not long reading |
| Black text on #427ACC | 4.88:1 | AA | Lc 34.6 | Non-text elements, placeholder text |
| #427ACC text on white | 4.29:1 | AA large text | Lc 69.4 | Content text, not long reading |
| #427ACC text on black | 4.88:1 | AA | Lc -32.2 | 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 600.
-
Step 50
50
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E3EBF6
oklch(93.7% 0.017 256.3)
-
Step 200
200
#CBDAF1
oklch(88.4% 0.036 258.9)
-
Step 300
300
#A8C2EA
oklch(80.8% 0.064 258.9)
-
Step 400
400
#79A2DF
oklch(70.7% 0.101 258.1)
-
Step 500
500
#568AD6
oklch(63.1% 0.128 257.8)
-
Step 600
600 (this color)
#427ACC
oklch(58.2% 0.14 258)
-
Step 700
700
#2D5FA9
oklch(49% 0.13 258.3)
-
Step 800
800
#264E89
oklch(42.7% 0.108 258.2)
-
Step 900
900
#24416D
oklch(37.6% 0.084 258.5)
-
Step 950
950
#152740
oklch(27.1% 0.053 256.9)
#427ACC 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) | #5481CF | 0.028 |
| Deuteranopia (no green cones) | #3F74CA | 0.017 |
| Tritanopia (no blue cones) | #008D99 | 0.112 |
| Achromatopsia (no color) | #7A7A7A | 0.140 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #427ACC
#427ACC
oklch(58.2% 0.14 258)
- #A27000
#A27000
oklch(58.2% 0.121 77.7)
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 #427ACC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.023
- Water Blue #0E87CC ΔE 0.041
- Cool Blue #4984B8 ΔE 0.047
- Steel Blue #4682B4 ΔE 0.048
- Nice Blue #107AB0 ΔE 0.056
- Flat Blue #3C73A8 ΔE 0.057
- French Blue #436BAD ΔE 0.058
- Royal Blue #4169E1 ΔE 0.058
Use #427ACC 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.