#517DBB
Closest named color: Cool Blue (#4984B8). oklch(58.6% 0.108 257.1), rgb(81, 125, 187).
Aa
Black text reads best on this color (5.00:1).
About this color
#517DBB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.108 and its hue 257°. Its hue sits on the cool side of the wheel. The nearest named color is Cool Blue (#4984B8), ΔE 0.022 away. Black text reads best on it, at 5.00:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.108) |
| Temperature | cool |
| Nearest name | Cool Blue (#4984B8) |
| Black text | 5.00:1 |
| White text | 4.19:1 |
Values
| HEX | #517DBB |
| RGB | rgb(81, 125, 187) |
| HSL | hsl(215, 44%, 53%) |
| OKLCH | oklch(58.6% 0.108 257.1) |
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 #517DBB | 4.19:1 | AA large text | Lc -74.3 | Content text, not long reading |
| Black text on #517DBB | 5.00:1 | AA | Lc 35.3 | Non-text elements, placeholder text |
| #517DBB text on white | 4.19:1 | AA large text | Lc 68.8 | Content text, not long reading |
| #517DBB text on black | 5.00:1 | AA | Lc -32.9 | 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
#ADC2E0
oklch(80.8% 0.048 257.3)
-
Step 400
400
#82A3D1
oklch(70.8% 0.077 256.8)
-
Step 500
500
#628BC5
oklch(63.1% 0.099 257.1)
-
Step 600
600 (this color)
#517DBB
oklch(58.6% 0.108 257.1)
-
Step 700
700
#3A6199
oklch(49.1% 0.101 257.5)
-
Step 800
800
#30507C
oklch(42.8% 0.083 256.7)
-
Step 900
900
#2B4264
oklch(37.7% 0.065 258)
-
Step 950
950
#19273A
oklch(27% 0.041 256.3)
#517DBB 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) | #6481BE | 0.026 |
| Deuteranopia (no green cones) | #5677BA | 0.017 |
| Tritanopia (no blue cones) | #008B93 | 0.096 |
| Achromatopsia (no color) | #7C7C7C | 0.108 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #517DBB
#517DBB
oklch(58.6% 0.108 257.1)
- #9F7324
#9F7324
oklch(58.6% 0.108 77.8)
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 #517DBB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Cool Blue #4984B8 ΔE 0.022
- Steel Blue #4682B4 ΔE 0.022
- Windows Blue #3778BF ΔE 0.031
- Off Blue #5684AE ΔE 0.033
- Dusty Blue #5A86AD ΔE 0.040
- Flat Blue #3C73A8 ΔE 0.046
- Water Blue #0E87CC ΔE 0.047
- Stormy Blue #507B9C ΔE 0.048
Use #517DBB 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.