#427FCF
Closest named color: Windows Blue (#3778BF). oklch(59.4% 0.138 256.1), rgb(66, 127, 207).
Aa
Black text reads best on this color (5.16:1).
About this color
#427FCF is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.138 and its hue 256°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.032 away. Black text reads best on it, at 5.16:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.138) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.16:1 |
| White text | 4.06:1 |
Values
| HEX | #427FCF |
| RGB | rgb(66, 127, 207) |
| HSL | hsl(214, 59%, 54%) |
| OKLCH | oklch(59.4% 0.138 256.1) |
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 #427FCF | 4.06:1 | AA large text | Lc -73.1 | Content text, not long reading |
| Black text on #427FCF | 5.16:1 | AA | Lc 36.5 | Non-text elements, placeholder text |
| #427FCF text on white | 4.06:1 | AA large text | Lc 67.6 | Content text, not long reading |
| #427FCF text on black | 5.16:1 | AA | Lc -34.1 | 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EBF7
oklch(93.7% 0.019 255.5)
-
Step 200
200
#C9DBF2
oklch(88.5% 0.037 254.6)
-
Step 300
300
#A4C3EC
oklch(80.9% 0.067 255.5)
-
Step 400
400
#73A3E3
oklch(70.7% 0.108 255.9)
-
Step 500
500 (this color)
#427FCF
oklch(59.4% 0.138 256.1)
-
Step 600
600
#2F73C9
oklch(55.7% 0.15 256)
-
Step 700
700
#2160AE
oklch(49.2% 0.14 255.9)
-
Step 800
800
#1D4E8D
oklch(42.6% 0.117 256.3)
-
Step 900
900
#1E4270
oklch(37.8% 0.089 255.7)
-
Step 950
950
#122742
oklch(27.1% 0.057 255.5)
#427FCF 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) | #5B85D2 | 0.032 |
| Deuteranopia (no green cones) | #4678CD | 0.018 |
| Tritanopia (no blue cones) | #00929D | 0.110 |
| Achromatopsia (no color) | #7E7E7E | 0.138 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #427FCF
#427FCF
oklch(59.4% 0.138 256.1)
- #A87200
#A87200
oklch(59.3% 0.125 76)
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 #427FCF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.032
- Water Blue #0E87CC ΔE 0.033
- Cool Blue #4984B8 ΔE 0.042
- Steel Blue #4682B4 ΔE 0.045
- Dark Sky Blue #448EE4 ΔE 0.048
- Off Blue #5684AE ΔE 0.059
- Nice Blue #107AB0 ΔE 0.060
- Soft Blue #6488EA ΔE 0.060
Use #427FCF 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.