#517DB3
Closest named color: Steel Blue (#4682B4). oklch(58.1% 0.097 254.2), rgb(81, 125, 179).
Aa
Black text reads best on this color (4.93:1).
About this color
#517DB3 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.097 and its hue 254°. Its hue sits on the cool side of the wheel. The nearest named color is Steel Blue (#4682B4), ΔE 0.016 away. Black text reads best on it, at 4.93:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.097) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 4.93:1 |
| White text | 4.25:1 |
Values
| HEX | #517DB3 |
| RGB | rgb(81, 125, 179) |
| HSL | hsl(213, 39%, 51%) |
| OKLCH | oklch(58.1% 0.097 254.2) |
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 #517DB3 | 4.25:1 | AA large text | Lc -74.8 | Content text, not long reading |
| Black text on #517DB3 | 4.93:1 | AA | Lc 34.8 | Non-text elements, placeholder text |
| #517DB3 text on white | 4.25:1 | AA large text | Lc 69.3 | Content text, not long reading |
| #517DB3 text on black | 4.93:1 | AA | Lc -32.4 | 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
#F3F6F9
oklch(97.2% 0.005 247.9)
-
Step 100
100
#E4EAF2
oklch(93.5% 0.013 255.5)
-
Step 200
200
#CFDAE9
oklch(88.5% 0.024 256.1)
-
Step 300
300
#AEC3DD
oklch(81% 0.043 253.8)
-
Step 400
400
#83A3CC
oklch(70.7% 0.07 254.8)
-
Step 500
500
#638CBF
oklch(63.1% 0.09 254.4)
-
Step 600
600 (this color)
#517DB3
oklch(58.1% 0.097 254.2)
-
Step 700
700
#3B6293
oklch(49% 0.091 254.9)
-
Step 800
800
#315077
oklch(42.6% 0.075 254.8)
-
Step 900
900
#2B4360
oklch(37.7% 0.058 253.8)
-
Step 950
950
#1A2738
oklch(26.9% 0.037 255.4)
#517DB3 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) | #6780B5 | 0.029 |
| Deuteranopia (no green cones) | #5B76B2 | 0.021 |
| Tritanopia (no blue cones) | #148990 | 0.085 |
| Achromatopsia (no color) | #7B7B7B | 0.097 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517DB3
#517DB3
oklch(58.1% 0.097 254.2)
- #9D7132
#9D7132
oklch(58.1% 0.097 73.5)
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 #517DB3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Steel Blue #4682B4 ΔE 0.016
- Cool Blue #4984B8 ΔE 0.020
- Off Blue #5684AE ΔE 0.025
- Dusty Blue #5A86AD ΔE 0.032
- Stormy Blue #507B9C ΔE 0.036
- Windows Blue #3778BF ΔE 0.036
- Cerulean #457B9D ΔE 0.038
- Flat Blue #3C73A8 ΔE 0.040
Use #517DB3 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.