#427EC3
Closest named color: Windows Blue (#3778BF). oklch(58.5% 0.124 253.4), rgb(66, 126, 195).
Aa
Black text reads best on this color (5.00:1).
About this color
#427EC3 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.124 and its hue 253°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.021 away. Black text reads best on it, at 5.00:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.124) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.00:1 |
| White text | 4.19:1 |
Values
| HEX | #427EC3 |
| RGB | rgb(66, 126, 195) |
| HSL | hsl(212, 52%, 51%) |
| OKLCH | oklch(58.5% 0.124 253.4) |
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 #427EC3 | 4.19:1 | AA large text | Lc -74.2 | Content text, not long reading |
| Black text on #427EC3 | 5.00:1 | AA | Lc 35.4 | Non-text elements, placeholder text |
| #427EC3 text on white | 4.19:1 | AA large text | Lc 68.7 | Content text, not long reading |
| #427EC3 text on black | 5.00:1 | AA | Lc -33.0 | 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
#F2F6FA
oklch(97.1% 0.007 247.9)
-
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
#A8C3E4
oklch(80.8% 0.055 253.6)
-
Step 400
400
#79A4D7
oklch(70.7% 0.089 253.2)
-
Step 500
500
#558CCD
oklch(63.1% 0.115 253.6)
-
Step 600
600 (this color)
#427EC3
oklch(58.5% 0.124 253.4)
-
Step 700
700
#2B62A0
oklch(49.1% 0.115 253.5)
-
Step 800
800
#255082
oklch(42.7% 0.096 253.9)
-
Step 900
900
#234368
oklch(37.7% 0.074 253.3)
-
Step 950
950
#15273D
oklch(26.9% 0.048 254.2)
#427EC3 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) | #6082C6 | 0.035 |
| Deuteranopia (no green cones) | #4D76C2 | 0.023 |
| Tritanopia (no blue cones) | #008E97 | 0.098 |
| Achromatopsia (no color) | #7C7C7C | 0.124 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #427EC3
#427EC3
oklch(58.5% 0.124 253.4)
- #A76E03
#A76E03
oklch(58.4% 0.124 73.2)
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 #427EC3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.021
- Cool Blue #4984B8 ΔE 0.028
- Steel Blue #4682B4 ΔE 0.029
- Water Blue #0E87CC ΔE 0.033
- Off Blue #5684AE ΔE 0.045
- Nice Blue #107AB0 ΔE 0.045
- Flat Blue #3C73A8 ΔE 0.049
- Dusty Blue #5A86AD ΔE 0.052
Use #427EC3 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.