#517DC4
Closest named color: Windows Blue (#3778BF). oklch(59% 0.12 259.6), rgb(81, 125, 196).
Aa
Black text reads best on this color (5.08:1).
About this color
#517DC4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.120 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.031 away. Black text reads best on it, at 5.08:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.120) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.08:1 |
| White text | 4.13:1 |
Values
| HEX | #517DC4 |
| RGB | rgb(81, 125, 196) |
| HSL | hsl(217, 49%, 54%) |
| OKLCH | oklch(59% 0.12 259.6) |
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 #517DC4 | 4.13:1 | AA large text | Lc -73.7 | Content text, not long reading |
| Black text on #517DC4 | 5.08:1 | AA | Lc 35.8 | Non-text elements, placeholder text |
| #517DC4 text on white | 4.13:1 | AA large text | Lc 68.2 | Content text, not long reading |
| #517DC4 text on black | 5.08:1 | AA | Lc -33.4 | 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
#F3F6FA
oklch(97.2% 0.006 255.5)
-
Step 100
100
#E4EAF5
oklch(93.6% 0.016 262.8)
-
Step 200
200
#CEDAED
oklch(88.5% 0.029 259.6)
-
Step 300
300
#ACC2E4
oklch(80.9% 0.054 259)
-
Step 400
400
#81A2D7
oklch(70.8% 0.086 259.7)
-
Step 500
500
#618ACC
oklch(63.2% 0.11 259.6)
-
Step 600
600 (this color)
#517DC4
oklch(59% 0.12 259.6)
-
Step 700
700
#39609F
oklch(49.2% 0.111 259.6)
-
Step 800
800
#2F4E81
oklch(42.6% 0.093 259.9)
-
Step 900
900
#2A4167
oklch(37.6% 0.072 260)
-
Step 950
950
#19273D
oklch(27.2% 0.046 259.2)
#517DC4 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) | #5F83C7 | 0.025 |
| Deuteranopia (no green cones) | #5078C3 | 0.014 |
| Tritanopia (no blue cones) | #008D97 | 0.105 |
| Achromatopsia (no color) | #7D7D7D | 0.120 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517DC4
#517DC4
oklch(59% 0.12 259.6)
- #A3740A
#A3740A
oklch(59.2% 0.12 79.6)
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 #517DC4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.031
- Cool Blue #4984B8 ΔE 0.031
- Steel Blue #4682B4 ΔE 0.033
- Water Blue #0E87CC ΔE 0.044
- Off Blue #5684AE ΔE 0.044
- Dusty Blue #5A86AD ΔE 0.050
- Faded Blue #658CBB ΔE 0.055
- Flat Blue #3C73A8 ΔE 0.055
Use #517DC4 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.