#517CC5
Closest named color: Windows Blue (#3778BF). oklch(58.9% 0.122 260.4), rgb(81, 124, 197).
Aa
Black text reads best on this color (5.03:1).
About this color
#517CC5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.122 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.030 away. Black text reads best on it, at 5.03:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.122) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.03:1 |
| White text | 4.16:1 |
Values
| HEX | #517CC5 |
| RGB | rgb(81, 124, 197) |
| HSL | hsl(218, 50%, 55%) |
| OKLCH | oklch(58.9% 0.122 260.4) |
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 #517CC5 | 4.16:1 | AA large text | Lc -74.0 | Content text, not long reading |
| Black text on #517CC5 | 5.03:1 | AA | Lc 35.6 | Non-text elements, placeholder text |
| #517CC5 text on white | 4.16:1 | AA large text | Lc 68.5 | Content text, not long reading |
| #517CC5 text on black | 5.03:1 | AA | Lc -33.1 | 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 600.
-
Step 50
50
#F3F6FB
oklch(97.2% 0.007 260.7)
-
Step 100
100
#E4EAF5
oklch(93.6% 0.016 262.8)
-
Step 200
200
#CEDAEE
oklch(88.5% 0.03 260.7)
-
Step 300
300
#ACC2E5
oklch(80.9% 0.055 259.6)
-
Step 400
400
#81A1D8
oklch(70.6% 0.089 261)
-
Step 500
500
#6189CD
oklch(63% 0.112 260.6)
-
Step 600
600 (this color)
#517CC5
oklch(58.9% 0.122 260.4)
-
Step 700
700
#395FA1
oklch(49.1% 0.115 260.7)
-
Step 800
800
#2F4E82
oklch(42.7% 0.094 260.2)
-
Step 900
900
#2A4168
oklch(37.6% 0.073 260.4)
-
Step 950
950
#19263D
oklch(26.9% 0.047 261.3)
#517CC5 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) | #5D82C8 | 0.023 |
| Deuteranopia (no green cones) | #4E77C3 | 0.015 |
| Tritanopia (no blue cones) | #008C97 | 0.106 |
| Achromatopsia (no color) | #7C7C7C | 0.122 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517CC5
#517CC5
oklch(58.9% 0.122 260.4)
- #A27300
#A27300
oklch(58.8% 0.122 80.1)
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 #517CC5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.030
- Cool Blue #4984B8 ΔE 0.034
- Steel Blue #4682B4 ΔE 0.036
- Water Blue #0E87CC ΔE 0.045
- Off Blue #5684AE ΔE 0.047
- Dusty Blue #5A86AD ΔE 0.053
- Flat Blue #3C73A8 ΔE 0.055
- Faded Blue #658CBB ΔE 0.058
Use #517CC5 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.