#517BB8
Closest named color: Steel Blue (#4682B4). oklch(57.9% 0.106 257.7), rgb(81, 123, 184).
Aa
Black text reads best on this color (4.87:1).
About this color
#517BB8 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.106 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Steel Blue (#4682B4), ΔE 0.024 away. Black text reads best on it, at 4.87:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.106) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 4.87:1 |
| White text | 4.30:1 |
Values
| HEX | #517BB8 |
| RGB | rgb(81, 123, 184) |
| HSL | hsl(216, 42%, 52%) |
| OKLCH | oklch(57.9% 0.106 257.7) |
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 #517BB8 | 4.30:1 | AA large text | Lc -75.2 | Fine for body text |
| Black text on #517BB8 | 4.87:1 | AA | Lc 34.4 | Non-text elements, placeholder text |
| #517BB8 text on white | 4.30:1 | AA large text | Lc 69.7 | Content text, not long reading |
| #517BB8 text on black | 4.87:1 | AA | Lc -32.0 | 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
#CFDAEB
oklch(88.5% 0.026 259)
-
Step 300
300
#AEC2E0
oklch(80.9% 0.048 258.4)
-
Step 400
400
#83A2D0
oklch(70.6% 0.076 258.1)
-
Step 500
500
#648BC4
oklch(63.2% 0.097 257.8)
-
Step 600
600 (this color)
#517BB8
oklch(57.9% 0.106 257.7)
-
Step 700
700
#3B6198
oklch(49.1% 0.099 257.6)
-
Step 800
800
#314F7B
oklch(42.6% 0.082 257.9)
-
Step 900
900
#2C4263
oklch(37.7% 0.063 258.3)
-
Step 950
950
#1A273A
oklch(27% 0.04 257.8)
#517BB8 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) | #627FBB | 0.024 |
| Deuteranopia (no green cones) | #5575B7 | 0.016 |
| Tritanopia (no blue cones) | #088991 | 0.095 |
| Achromatopsia (no color) | #7A7A7A | 0.106 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517BB8
#517BB8
oklch(57.9% 0.106 257.7)
- #9C7125
#9C7125
oklch(57.9% 0.105 77.6)
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 #517BB8, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Steel Blue #4682B4 ΔE 0.024
- Cool Blue #4984B8 ΔE 0.026
- Windows Blue #3778BF ΔE 0.029
- Off Blue #5684AE ΔE 0.034
- Flat Blue #3C73A8 ΔE 0.040
- Dusty Blue #5A86AD ΔE 0.042
- Stormy Blue #507B9C ΔE 0.045
- Dull Blue #49759C ΔE 0.046
Use #517BB8 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.