#3F7ECD
Closest named color: Windows Blue (#3778BF). oklch(59% 0.138 255.3), rgb(63, 126, 205).
Aa
Black text reads best on this color (5.07:1).
About this color
#3F7ECD is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.138 and its hue 255°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.027 away. Black text reads best on it, at 5.07:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.138) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.07:1 |
| White text | 4.13:1 |
Values
| HEX | #3F7ECD |
| RGB | rgb(63, 126, 205) |
| HSL | hsl(213, 59%, 53%) |
| OKLCH | oklch(59% 0.138 255.3) |
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 #3F7ECD | 4.13:1 | AA large text | Lc -73.7 | Content text, not long reading |
| Black text on #3F7ECD | 5.07:1 | AA | Lc 35.9 | Non-text elements, placeholder text |
| #3F7ECD text on white | 4.13:1 | AA large text | Lc 68.2 | Content text, not long reading |
| #3F7ECD text on black | 5.07:1 | AA | Lc -33.5 | 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
#E2EBF6
oklch(93.7% 0.018 253.3)
-
Step 200
200
#CADBF0
oklch(88.5% 0.034 253.7)
-
Step 300
300
#A6C3E9
oklch(80.9% 0.063 255.3)
-
Step 400
400
#76A3DE
oklch(70.7% 0.1 255.5)
-
Step 500
500
#528BD5
oklch(63.1% 0.127 255.6)
-
Step 600
600 (this color)
#3F7ECD
oklch(59% 0.138 255.3)
-
Step 700
700
#2761A7
oklch(49.2% 0.127 255.1)
-
Step 800
800
#224F88
oklch(42.7% 0.107 255.7)
-
Step 900
900
#21426C
oklch(37.6% 0.082 255.4)
-
Step 950
950
#142740
oklch(27% 0.053 255.8)
#3F7ECD 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) | #5A84D0 | 0.033 |
| Deuteranopia (no green cones) | #4477CB | 0.019 |
| Tritanopia (no blue cones) | #00909B | 0.108 |
| Achromatopsia (no color) | #7D7D7D | 0.138 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F7ECD
#3F7ECD
oklch(59% 0.138 255.3)
- #A77100
#A77100
oklch(59% 0.124 75.7)
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 #3F7ECD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.027
- Water Blue #0E87CC ΔE 0.032
- Cool Blue #4984B8 ΔE 0.041
- Steel Blue #4682B4 ΔE 0.043
- Dark Sky Blue #448EE4 ΔE 0.052
- Nice Blue #107AB0 ΔE 0.056
- Off Blue #5684AE ΔE 0.058
- Flat Blue #3C73A8 ΔE 0.061
Use #3F7ECD 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.