#427BD3
Closest named color: Windows Blue (#3778BF). oklch(58.8% 0.148 258.9), rgb(66, 123, 211).
Aa
Black text reads best on this color (5.00:1).
About this color
#427BD3 is a medium-dark, vivid blue. In OKLCH its lightness is 59%, its chroma 0.148 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.033 away. Black text reads best on it, at 5.00:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | vivid (0.148) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.00:1 |
| White text | 4.19:1 |
Values
| HEX | #427BD3 |
| RGB | rgb(66, 123, 211) |
| HSL | hsl(216, 62%, 54%) |
| OKLCH | oklch(58.8% 0.148 258.9) |
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 #427BD3 | 4.19:1 | AA large text | Lc -74.1 | Content text, not long reading |
| Black text on #427BD3 | 5.00:1 | AA | Lc 35.5 | Non-text elements, placeholder text |
| #427BD3 text on white | 4.19:1 | AA large text | Lc 68.6 | Content text, not long reading |
| #427BD3 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
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E2EAF7
oklch(93.5% 0.02 260.2)
-
Step 200
200
#CBDAF2
oklch(88.5% 0.037 259.8)
-
Step 300
300
#A7C2EC
oklch(80.8% 0.067 259.1)
-
Step 400
400
#78A2E3
oklch(70.8% 0.106 258.9)
-
Step 500
500
#5489DB
oklch(63.1% 0.137 258.8)
-
Step 600
600 (this color)
#427BD3
oklch(58.8% 0.148 258.9)
-
Step 700
700
#2B5EAD
oklch(49% 0.138 259)
-
Step 800
800
#254D8C
oklch(42.6% 0.114 259.2)
-
Step 900
900
#234170
oklch(37.7% 0.088 259.1)
-
Step 950
950
#152642
oklch(27% 0.057 259.9)
#427BD3 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) | #5283D6 | 0.029 |
| Deuteranopia (no green cones) | #3A75D1 | 0.019 |
| Tritanopia (no blue cones) | #008F9D | 0.117 |
| Achromatopsia (no color) | #7C7C7C | 0.148 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #427BD3
#427BD3
oklch(58.8% 0.148 258.9)
- #A37200
#A37200
oklch(58.7% 0.122 78.7)
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 #427BD3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.033
- Water Blue #0E87CC ΔE 0.042
- Cool Blue #4984B8 ΔE 0.054
- Royal Blue #4169E1 ΔE 0.054
- Dark Sky Blue #448EE4 ΔE 0.054
- Steel Blue #4682B4 ΔE 0.056
- Soft Blue #6488EA ΔE 0.062
- Nice Blue #107AB0 ΔE 0.065
Use #427BD3 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.