#517BB4
Closest named color: Steel Blue (#4682B4). oklch(57.7% 0.1 256.3), rgb(81, 123, 180).
Aa
Black text reads best on this color (4.84:1).
About this color
#517BB4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 58%, its chroma 0.100 and its hue 256°. 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 4.84:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | moderately saturated (0.100) |
| Temperature | cool |
| Nearest name | Steel Blue (#4682B4) |
| Black text | 4.84:1 |
| White text | 4.33:1 |
Values
| HEX | #517BB4 |
| RGB | rgb(81, 123, 180) |
| HSL | hsl(215, 40%, 51%) |
| OKLCH | oklch(57.7% 0.1 256.3) |
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 #517BB4 | 4.33:1 | AA large text | Lc -75.4 | Fine for body text |
| Black text on #517BB4 | 4.84:1 | AA | Lc 34.2 | Non-text elements, placeholder text |
| #517BB4 text on white | 4.33:1 | AA large text | Lc 69.9 | Content text, not long reading |
| #517BB4 text on black | 4.84:1 | AA | Lc -31.8 | 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
#F3F6FA
oklch(97.2% 0.006 255.5)
-
Step 100
100
#E4EAF3
oklch(93.5% 0.014 258.3)
-
Step 200
200
#CFDAEA
oklch(88.5% 0.025 257.6)
-
Step 300
300
#AEC2DE
oklch(80.8% 0.045 256.8)
-
Step 400
400
#83A3CE
oklch(70.7% 0.073 255.9)
-
Step 500
500
#648BC1
oklch(63% 0.093 256.7)
-
Step 600
600 (this color)
#517BB4
oklch(57.7% 0.1 256.3)
-
Step 700
700
#3C6295
oklch(49.2% 0.093 256.2)
-
Step 800
800
#325079
oklch(42.8% 0.077 256.5)
-
Step 900
900
#2C4261
oklch(37.6% 0.06 257)
-
Step 950
950
#1A2739
oklch(27% 0.038 256.7)
#517BB4 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) | #647FB6 | 0.026 |
| Deuteranopia (no green cones) | #5875B3 | 0.017 |
| Tritanopia (no blue cones) | #13888F | 0.090 |
| Achromatopsia (no color) | #797979 | 0.100 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517BB4
#517BB4
oklch(57.7% 0.1 256.3)
- #9B712C
#9B712C
oklch(57.8% 0.1 76.6)
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 #517BB4, 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 0.025
- Off Blue #5684AE ΔE 0.031
- Windows Blue #3778BF ΔE 0.032
- Flat Blue #3C73A8 ΔE 0.037
- Stormy Blue #507B9C ΔE 0.038
- Dusty Blue #5A86AD ΔE 0.038
- Cerulean #457B9D ΔE 0.040
Use #517BB4 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.