#517DC0
Closest named color: Cool Blue (#4984B8). oklch(58.8% 0.114 258.6), rgb(81, 125, 192).
Aa
Black text reads best on this color (5.04:1).
About this color
#517DC0 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.114 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.026 away. Black text reads best on it, at 5.04:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.114) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.04:1 |
| White text | 4.16:1 |
Values
| HEX | #517DC0 |
| RGB | rgb(81, 125, 192) |
| HSL | hsl(216, 47%, 54%) |
| OKLCH | oklch(58.8% 0.114 258.6) |
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 #517DC0 | 4.16:1 | AA large text | Lc -74.0 | Content text, not long reading |
| Black text on #517DC0 | 5.04:1 | AA | Lc 35.6 | Non-text elements, placeholder text |
| #517DC0 text on white | 4.16:1 | AA large text | Lc 68.5 | Content text, not long reading |
| #517DC0 text on black | 5.04:1 | AA | Lc -33.2 | 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
#E4EAF4
oklch(93.5% 0.015 260.7)
-
Step 200
200
#CEDAEC
oklch(88.5% 0.028 258.4)
-
Step 300
300
#ADC2E2
oklch(80.9% 0.051 258.7)
-
Step 400
400
#81A2D4
oklch(70.7% 0.082 258.5)
-
Step 500
500
#618AC9
oklch(63% 0.106 258.7)
-
Step 600
600 (this color)
#517DC0
oklch(58.8% 0.114 258.6)
-
Step 700
700
#39609C
oklch(49% 0.107 258.7)
-
Step 800
800
#304F7F
oklch(42.8% 0.088 258.9)
-
Step 900
900
#2A4266
oklch(37.7% 0.069 258.3)
-
Step 950
950
#19273C
oklch(27.1% 0.044 258.3)
#517DC0 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) | #6182C3 | 0.025 |
| Deuteranopia (no green cones) | #5377BF | 0.016 |
| Tritanopia (no blue cones) | #008C95 | 0.101 |
| Achromatopsia (no color) | #7C7C7C | 0.114 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517DC0
#517DC0
oklch(58.8% 0.114 258.6)
- #A17319
#A17319
oklch(58.8% 0.114 78.5)
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 #517DC0, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.026
- Steel Blue #4682B4 ΔE 0.028
- Windows Blue #3778BF ΔE 0.030
- Off Blue #5684AE ΔE 0.039
- Water Blue #0E87CC ΔE 0.045
- Dusty Blue #5A86AD ΔE 0.045
- Flat Blue #3C73A8 ΔE 0.051
- Faded Blue #658CBB ΔE 0.053
Use #517DC0 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.