#517FC4
Closest named color: Cool Blue (#4984B8). oklch(59.5% 0.118 258.3), rgb(81, 127, 196).
Aa
Black text reads best on this color (5.18:1).
About this color
#517FC4 is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.118 and its hue 258°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.027 away. Black text reads best on it, at 5.18:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.118) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.18:1 |
| White text | 4.05:1 |
Values
| HEX | #517FC4 |
| RGB | rgb(81, 127, 196) |
| HSL | hsl(216, 49%, 54%) |
| OKLCH | oklch(59.5% 0.118 258.3) |
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 #517FC4 | 4.05:1 | AA large text | Lc -73.1 | Content text, not long reading |
| Black text on #517FC4 | 5.18:1 | AA | Lc 36.5 | Non-text elements, placeholder text |
| #517FC4 text on white | 4.05:1 | AA large text | Lc 67.6 | Content text, not long reading |
| #517FC4 text on black | 5.18:1 | AA | Lc -34.1 | 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 500.
-
Step 50
50
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E3EAF5
oklch(93.5% 0.017 259.4)
-
Step 200
200
#CCDAEF
oklch(88.4% 0.033 258.4)
-
Step 300
300
#AAC2E6
oklch(80.8% 0.057 258.4)
-
Step 400
400
#7DA2DA
oklch(70.7% 0.092 258.5)
-
Step 500
500 (this color)
#517FC4
oklch(59.5% 0.118 258.3)
-
Step 600
600
#4173BD
oklch(55.7% 0.128 258.1)
-
Step 700
700
#3360A3
oklch(49.1% 0.119 258.3)
-
Step 800
800
#2B4F84
oklch(42.8% 0.098 258)
-
Step 900
900
#27426A
oklch(37.8% 0.076 258.1)
-
Step 950
950
#17273E
oklch(27.1% 0.048 257.5)
#517FC4 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) | #6284C7 | 0.025 |
| Deuteranopia (no green cones) | #5379C3 | 0.016 |
| Tritanopia (no blue cones) | #008E98 | 0.102 |
| Achromatopsia (no color) | #7E7E7E | 0.118 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517FC4
#517FC4
oklch(59.5% 0.118 258.3)
- #A47515
#A47515
oklch(59.5% 0.118 78.9)
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 #517FC4, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.027
- Steel Blue #4682B4 ΔE 0.031
- Windows Blue #3778BF ΔE 0.034
- Off Blue #5684AE ΔE 0.041
- Water Blue #0E87CC ΔE 0.042
- Dusty Blue #5A86AD ΔE 0.046
- Faded Blue #658CBB ΔE 0.050
- Dark Sky Blue #448EE4 ΔE 0.056
Use #517FC4 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.