#517CB8
Closest named color: Steel Blue (#4682B4). oklch(58.2% 0.105 256.9), rgb(81, 124, 184).
Aa
Black text reads best on this color (4.92:1).
About this color
#517CB8 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.105 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Steel Blue (#4682B4), ΔE 0.021 away. Black text reads best on it, at 4.92:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.105) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 4.92:1 |
| White text | 4.26:1 |
Values
| HEX | #517CB8 |
| RGB | rgb(81, 124, 184) |
| HSL | hsl(215, 42%, 52%) |
| OKLCH | oklch(58.2% 0.105 256.9) |
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 #517CB8 | 4.26:1 | AA large text | Lc -74.8 | Content text, not long reading |
| Black text on #517CB8 | 4.92:1 | AA | Lc 34.8 | Non-text elements, placeholder text |
| #517CB8 text on white | 4.26:1 | AA large text | Lc 69.3 | Content text, not long reading |
| #517CB8 text on black | 4.92:1 | 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
#E4EAF3
oklch(93.5% 0.014 258.3)
-
Step 200
200
#CEDAEB
oklch(88.4% 0.027 257)
-
Step 300
300
#AEC2DF
oklch(80.8% 0.047 257.6)
-
Step 400
400
#83A3D0
oklch(70.8% 0.075 256.9)
-
Step 500
500
#638BC3
oklch(63.1% 0.096 256.9)
-
Step 600
600 (this color)
#517CB8
oklch(58.2% 0.105 256.9)
-
Step 700
700
#3B6197
oklch(49% 0.097 257.3)
-
Step 800
800
#31507A
oklch(42.8% 0.079 256.4)
-
Step 900
900
#2B4263
oklch(37.6% 0.064 257.4)
-
Step 950
950
#1A273A
oklch(27% 0.04 257.8)
#517CB8 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) | #6480BB | 0.026 |
| Deuteranopia (no green cones) | #5776B7 | 0.017 |
| Tritanopia (no blue cones) | #078992 | 0.092 |
| Achromatopsia (no color) | #7A7A7A | 0.105 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517CB8
#517CB8
oklch(58.2% 0.105 256.9)
- #9D7227
#9D7227
oklch(58.2% 0.105 77.5)
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 #517CB8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Steel Blue #4682B4 ΔE 0.021
- Cool Blue #4984B8 ΔE 0.023
- Windows Blue #3778BF ΔE 0.031
- Off Blue #5684AE ΔE 0.032
- Dusty Blue #5A86AD ΔE 0.039
- Flat Blue #3C73A8 ΔE 0.042
- Stormy Blue #507B9C ΔE 0.044
- Cerulean #457B9D ΔE 0.045
Use #517CB8 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.