#517BBD
Closest named color: Windows Blue (#3778BF). oklch(58.2% 0.112 259.1), rgb(81, 123, 189).
Aa
Black text reads best on this color (4.91:1).
About this color
#517BBD is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.112 and its hue 259°. Its hue sits on the cool side of the wheel. The nearest named color is Windows Blue (#3778BF), ΔE 0.027 away. Black text reads best on it, at 4.91:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.112) |
| Temperature | cool |
| Nearest name | Windows Blue (#3778BF) |
| Black text | 4.91:1 |
| White text | 4.27:1 |
Values
| HEX | #517BBD |
| RGB | rgb(81, 123, 189) |
| HSL | hsl(217, 45%, 53%) |
| OKLCH | oklch(58.2% 0.112 259.1) |
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 #517BBD | 4.27:1 | AA large text | Lc -74.9 | Content text, not long reading |
| Black text on #517BBD | 4.91:1 | AA | Lc 34.7 | Non-text elements, placeholder text |
| #517BBD text on white | 4.27:1 | AA large text | Lc 69.4 | Content text, not long reading |
| #517BBD text on black | 4.91:1 | AA | Lc -32.3 | 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
#82A2D3
oklch(70.7% 0.081 258.7)
-
Step 500
500
#638AC8
oklch(63.1% 0.104 259.4)
-
Step 600
600 (this color)
#517BBD
oklch(58.2% 0.112 259.1)
-
Step 700
700
#3B609B
oklch(49% 0.104 259.4)
-
Step 800
800
#314F7E
oklch(42.8% 0.086 259.1)
-
Step 900
900
#2B4265
oklch(37.7% 0.067 258.5)
-
Step 950
950
#1A273B
oklch(27.1% 0.042 258.8)
#517BBD 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) | #6080C0 | 0.024 |
| Deuteranopia (no green cones) | #5276BC | 0.014 |
| Tritanopia (no blue cones) | #008A93 | 0.100 |
| Achromatopsia (no color) | #7A7A7A | 0.112 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517BBD
#517BBD
oklch(58.2% 0.112 259.1)
- #9E7219
#9E7219
oklch(58.2% 0.113 79.4)
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 #517BBD, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Windows Blue #3778BF ΔE 0.027
- Steel Blue #4682B4 ΔE 0.028
- Cool Blue #4984B8 ΔE 0.029
- Off Blue #5684AE ΔE 0.040
- Flat Blue #3C73A8 ΔE 0.045
- Dusty Blue #5A86AD ΔE 0.047
- Water Blue #0E87CC ΔE 0.048
- Nice Blue #107AB0 ΔE 0.051
Use #517BBD 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.