#517FCC
Closest named color: Cool Blue (#4984B8). oklch(59.9% 0.128 260.2), rgb(81, 127, 204).
Aa
Black text reads best on this color (5.25:1).
About this color
#517FCC is a medium-dark, moderately saturated blue. In OKLCH its lightness is 60%, its chroma 0.128 and its hue 260°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.038 away. Black text reads best on it, at 5.25:1.
| Hue family | Blues |
| Lightness | medium-dark (60%) |
| Chroma | moderately saturated (0.128) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.25:1 |
| White text | 3.99:1 |
Values
| HEX | #517FCC |
| RGB | rgb(81, 127, 204) |
| HSL | hsl(218, 55%, 56%) |
| OKLCH | oklch(59.9% 0.128 260.2) |
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 #517FCC | 3.99:1 | AA large text | Lc -72.6 | Content text, not long reading |
| Black text on #517FCC | 5.25:1 | AA | Lc 37.0 | Non-text elements, placeholder text |
| #517FCC text on white | 3.99:1 | AA large text | Lc 67.1 | Content text, not long reading |
| #517FCC text on black | 5.25:1 | AA | Lc -34.6 | 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
#E3EAF6
oklch(93.5% 0.018 261.3)
-
Step 200
200
#CCDAF1
oklch(88.5% 0.035 260.4)
-
Step 300
300
#A9C2EA
oklch(80.9% 0.063 259.7)
-
Step 400
400
#7CA1DF
oklch(70.6% 0.1 260.4)
-
Step 500
500 (this color)
#517FCC
oklch(59.9% 0.128 260.2)
-
Step 600
600
#4071C4
oklch(55.6% 0.14 260.3)
-
Step 700
700
#325EA9
oklch(49% 0.13 260.4)
-
Step 800
800
#2A4D89
oklch(42.6% 0.108 260.5)
-
Step 900
900
#26416E
oklch(37.8% 0.084 260.1)
-
Step 950
950
#172640
oklch(27% 0.053 260.8)
#517FCC 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) | #5E85CF | 0.023 |
| Deuteranopia (no green cones) | #4E7ACA | 0.014 |
| Tritanopia (no blue cones) | #00909C | 0.109 |
| Achromatopsia (no color) | #7F7F7F | 0.129 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517FCC
#517FCC
oklch(59.9% 0.128 260.2)
- #A67600
#A67600
oklch(59.9% 0.124 80.2)
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 #517FCC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.038
- Windows Blue #3778BF ΔE 0.038
- Steel Blue #4682B4 ΔE 0.042
- Water Blue #0E87CC ΔE 0.042
- Dark Sky Blue #448EE4 ΔE 0.048
- Off Blue #5684AE ΔE 0.052
- Soft Blue #6488EA ΔE 0.055
- Faded Blue #658CBB ΔE 0.056
Use #517FCC 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.