#517DC8
Closest named color: Windows Blue (#3778BF). oklch(59.3% 0.125 260.5), rgb(81, 125, 200).
Aa
Black text reads best on this color (5.11:1).
About this color
#517DC8 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.125 and its hue 260°. 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 5.11:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.125) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.11:1 |
| White text | 4.10:1 |
Values
| HEX | #517DC8 |
| RGB | rgb(81, 125, 200) |
| HSL | hsl(218, 52%, 55%) |
| OKLCH | oklch(59.3% 0.125 260.5) |
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 #517DC8 | 4.10:1 | AA large text | Lc -73.5 | Content text, not long reading |
| Black text on #517DC8 | 5.11:1 | AA | Lc 36.1 | Non-text elements, placeholder text |
| #517DC8 text on white | 4.10:1 | AA large text | Lc 68.0 | Content text, not long reading |
| #517DC8 text on black | 5.11:1 | AA | Lc -33.7 | 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
#CDDAEE
oklch(88.5% 0.031 258.9)
-
Step 300
300
#ACC2E6
oklch(81% 0.056 260.2)
-
Step 400
400
#80A1D9
oklch(70.6% 0.09 260.7)
-
Step 500
500
#6089CF
oklch(63.1% 0.116 260.6)
-
Step 600
600 (this color)
#517DC8
oklch(59.3% 0.125 260.5)
-
Step 700
700
#385FA2
oklch(49.1% 0.117 260.5)
-
Step 800
800
#2F4E83
oklch(42.7% 0.096 260.5)
-
Step 900
900
#2A4169
oklch(37.7% 0.075 260.9)
-
Step 950
950
#19263E
oklch(27% 0.049 262)
#517DC8 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) | #5D83CB | 0.023 |
| Deuteranopia (no green cones) | #4D78C6 | 0.015 |
| Tritanopia (no blue cones) | #008E99 | 0.108 |
| Achromatopsia (no color) | #7D7D7D | 0.125 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517DC8
#517DC8
oklch(59.3% 0.125 260.5)
- #A37500
#A37500
oklch(59.3% 0.123 81.1)
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 #517DC8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.033
- Cool Blue #4984B8 ΔE 0.036
- Steel Blue #4682B4 ΔE 0.039
- Water Blue #0E87CC ΔE 0.044
- Off Blue #5684AE ΔE 0.050
- Dusty Blue #5A86AD ΔE 0.055
- Dark Sky Blue #448EE4 ΔE 0.056
- Faded Blue #658CBB ΔE 0.057
Use #517DC8 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.