#517DD5
Closest named color: Windows Blue (#3778BF). oklch(60% 0.143 262.8), rgb(81, 125, 213).
Aa
Black text reads best on this color (5.24:1).
About this color
#517DD5 is a medium-dark, vivid blue. In OKLCH its lightness is 60%, its chroma 0.143 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.045 away. Black text reads best on it, at 5.24:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | vivid (0.143) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 5.24:1 |
| White text | 4.00:1 |
Values
| HEX | #517DD5 |
| RGB | rgb(81, 125, 213) |
| HSL | hsl(220, 61%, 58%) |
| OKLCH | oklch(60% 0.143 262.8) |
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 #517DD5 | 4.00:1 | AA large text | Lc -72.6 | Content text, not long reading |
| Black text on #517DD5 | 5.24:1 | AA | Lc 37.0 | Non-text elements, placeholder text |
| #517DD5 text on white | 4.00:1 | AA large text | Lc 67.1 | Content text, not long reading |
| #517DD5 text on black | 5.24:1 | AA | Lc -34.5 | 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 500.
-
Step 50
50
#F2F6FC
oklch(97.2% 0.009 258.3)
-
Step 100
100
#E3EAF8
oklch(93.6% 0.02 264.5)
-
Step 200
200
#CCDAF4
oklch(88.6% 0.039 262.9)
-
Step 300
300
#A9C1EF
oklch(80.9% 0.07 263.3)
-
Step 400
400
#7BA0E7
oklch(70.7% 0.112 262.8)
-
Step 500
500 (this color)
#517DD5
oklch(60% 0.143 262.8)
-
Step 600
600
#406ECD
oklch(55.5% 0.156 262.9)
-
Step 700
700
#325CB2
oklch(49.2% 0.145 262.7)
-
Step 800
800
#2A4B90
oklch(42.7% 0.121 263.1)
-
Step 900
900
#263F73
oklch(37.6% 0.094 263.2)
-
Step 950
950
#172543
oklch(26.9% 0.059 264)
#517DD5 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) | #5686D8 | 0.025 |
| Deuteranopia (no green cones) | #4279D3 | 0.020 |
| Tritanopia (no blue cones) | #00919F | 0.121 |
| Achromatopsia (no color) | #7F7F7F | 0.143 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517DD5
#517DD5
oklch(60% 0.143 262.8)
- #A47800
#A47800
oklch(60.1% 0.124 82.8)
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 #517DD5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.045
- Dark Sky Blue #448EE4 ΔE 0.046
- Soft Blue #6488EA ΔE 0.048
- Water Blue #0E87CC ΔE 0.049
- Cool Blue #4984B8 ΔE 0.054
- Steel Blue #4682B4 ΔE 0.058
- Royal Blue #4169E1 ΔE 0.062
- Cornflower #6A79F7 ΔE 0.062
Use #517DD5 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.