#427CC4
Closest named color: Windows Blue (#3778BF). oklch(58.1% 0.127 255), rgb(66, 124, 196).
Aa
Black text reads best on this color (4.91:1).
About this color
#427CC4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.127 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.017 away. Black text reads best on it, at 4.91:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.127) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.91:1 |
| White text | 4.27:1 |
Values
| HEX | #427CC4 |
| RGB | rgb(66, 124, 196) |
| HSL | hsl(213, 52%, 51%) |
| OKLCH | oklch(58.1% 0.127 255) |
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 #427CC4 | 4.27:1 | AA large text | Lc -74.8 | Content text, not long reading |
| Black text on #427CC4 | 4.91:1 | AA | Lc 34.8 | Non-text elements, placeholder text |
| #427CC4 text on white | 4.27:1 | AA large text | Lc 69.3 | Content text, not long reading |
| #427CC4 text on black | 4.91:1 | AA | Lc -32.4 | 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
#E3EBF5
oklch(93.7% 0.016 253.9)
-
Step 200
200
#CBDBEE
oklch(88.5% 0.031 252.7)
-
Step 300
300
#A8C3E6
oklch(80.9% 0.058 255)
-
Step 400
400
#79A3D9
oklch(70.6% 0.092 255)
-
Step 500
500
#568CCF
oklch(63.2% 0.117 254.6)
-
Step 600
600 (this color)
#427CC4
oklch(58.1% 0.127 255)
-
Step 700
700
#2D61A2
oklch(49% 0.118 255.4)
-
Step 800
800
#265083
oklch(42.8% 0.097 254.7)
-
Step 900
900
#244269
oklch(37.6% 0.076 255.7)
-
Step 950
950
#15273E
oklch(27% 0.049 255.2)
#427CC4 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) | #5C81C7 | 0.032 |
| Deuteranopia (no green cones) | #4A75C3 | 0.019 |
| Tritanopia (no blue cones) | #008D97 | 0.101 |
| Achromatopsia (no color) | #7A7A7A | 0.127 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #427CC4
#427CC4
oklch(58.1% 0.127 255)
- #A46E00
#A46E00
oklch(58% 0.122 75)
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 #427CC4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.017
- Cool Blue #4984B8 ΔE 0.034
- Steel Blue #4682B4 ΔE 0.034
- Water Blue #0E87CC ΔE 0.036
- Nice Blue #107AB0 ΔE 0.046
- Flat Blue #3C73A8 ΔE 0.048
- Off Blue #5684AE ΔE 0.050
- French Blue #436BAD ΔE 0.054
Use #427CC4 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.