#517EB5
Closest named color: Steel Blue (#4682B4). oklch(58.5% 0.099 254.2), rgb(81, 126, 181).
Aa
Black text reads best on this color (5.00:1).
About this color
#517EB5 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.099 and its hue 254°. Its hue sits on the cool side of the wheel. The nearest named color is Steel Blue (#4682B4), ΔE 0.015 away. Black text reads best on it, at 5.00:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.099) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 5.00:1 |
| White text | 4.19:1 |
Values
| HEX | #517EB5 |
| RGB | rgb(81, 126, 181) |
| HSL | hsl(213, 40%, 51%) |
| OKLCH | oklch(58.5% 0.099 254.2) |
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 #517EB5 | 4.19:1 | AA large text | Lc -74.3 | Content text, not long reading |
| Black text on #517EB5 | 5.00:1 | AA | Lc 35.3 | Non-text elements, placeholder text |
| #517EB5 text on white | 4.19:1 | AA large text | Lc 68.8 | Content text, not long reading |
| #517EB5 text on black | 5.00:1 | AA | Lc -32.8 | 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
#CEDAEA
oklch(88.4% 0.026 255.6)
-
Step 300
300
#ADC3DD
oklch(80.9% 0.044 252.7)
-
Step 400
400
#82A3CD
oklch(70.6% 0.072 254.7)
-
Step 500
500
#628CBF
oklch(63% 0.09 253.9)
-
Step 600
600 (this color)
#517EB5
oklch(58.5% 0.099 254.2)
-
Step 700
700
#3A6294
oklch(49% 0.093 254.8)
-
Step 800
800
#305078
oklch(42.6% 0.077 254.7)
-
Step 900
900
#2B4360
oklch(37.7% 0.058 253.8)
-
Step 950
950
#192738
oklch(26.9% 0.037 253.8)
#517EB5 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) | #6881B7 | 0.030 |
| Deuteranopia (no green cones) | #5B77B4 | 0.021 |
| Tritanopia (no blue cones) | #0F8A91 | 0.087 |
| Achromatopsia (no color) | #7C7C7C | 0.099 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517EB5
#517EB5
oklch(58.5% 0.099 254.2)
- #9E7231
#9E7231
oklch(58.4% 0.098 74.2)
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 #517EB5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Steel Blue #4682B4 ΔE 0.015
- Cool Blue #4984B8 ΔE 0.017
- Off Blue #5684AE ΔE 0.024
- Dusty Blue #5A86AD ΔE 0.031
- Windows Blue #3778BF ΔE 0.036
- Stormy Blue #507B9C ΔE 0.038
- Cerulean #457B9D ΔE 0.041
- Flat Blue #3C73A8 ΔE 0.043
Use #517EB5 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.