#427ED3
Closest named color: Windows Blue (#3778BF). oklch(59.5% 0.145 257.5), rgb(66, 126, 211).
Aa
Black text reads best on this color (5.15:1).
About this color
#427ED3 is a medium-dark, vivid blue. In OKLCH its lightness is 59%, its chroma 0.145 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.035 away. Black text reads best on it, at 5.15:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | vivid (0.145) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.15:1 |
| White text | 4.07:1 |
Values
| HEX | #427ED3 |
| RGB | rgb(66, 126, 211) |
| HSL | hsl(215, 62%, 54%) |
| OKLCH | oklch(59.5% 0.145 257.5) |
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 #427ED3 | 4.07:1 | AA large text | Lc -73.1 | Content text, not long reading |
| Black text on #427ED3 | 5.15:1 | AA | Lc 36.5 | Non-text elements, placeholder text |
| #427ED3 text on white | 4.07:1 | AA large text | Lc 67.6 | Content text, not long reading |
| #427ED3 text on black | 5.15:1 | AA | Lc -34.0 | 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 500.
-
Step 50
50
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E1EBF8
oklch(93.6% 0.021 254.9)
-
Step 200
200
#C9DBF4
oklch(88.6% 0.04 256.6)
-
Step 300
300
#A4C3EF
oklch(81% 0.071 257.1)
-
Step 400
400
#73A2E7
oklch(70.7% 0.114 257.9)
-
Step 500
500 (this color)
#427ED3
oklch(59.5% 0.145 257.5)
-
Step 600
600
#2F71CD
oklch(55.5% 0.157 257.6)
-
Step 700
700
#215EB1
oklch(49% 0.146 257.4)
-
Step 800
800
#1E4D90
oklch(42.6% 0.122 257.9)
-
Step 900
900
#1E4173
oklch(37.7% 0.095 257.6)
-
Step 950
950
#122643
oklch(26.9% 0.06 257.7)
#427ED3 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) | #5785D6 | 0.030 |
| Deuteranopia (no green cones) | #4078D1 | 0.017 |
| Tritanopia (no blue cones) | #00929E | 0.116 |
| Achromatopsia (no color) | #7E7E7E | 0.145 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #427ED3
#427ED3
oklch(59.5% 0.145 257.5)
- #A77300
#A77300
oklch(59.4% 0.124 77.3)
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 #427ED3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.035
- Water Blue #0E87CC ΔE 0.037
- Dark Sky Blue #448EE4 ΔE 0.047
- Cool Blue #4984B8 ΔE 0.049
- Steel Blue #4682B4 ΔE 0.052
- Soft Blue #6488EA ΔE 0.057
- Royal Blue #4169E1 ΔE 0.061
- Nice Blue #107AB0 ΔE 0.065
Use #427ED3 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.