#3580CB
Closest named color: Water Blue (#0E87CC). oklch(59% 0.137 251.3), rgb(53, 128, 203).
Aa
Black text reads best on this color (5.10:1).
About this color
#3580CB is a medium-dark, moderately saturated blue. In OKLCH its lightness is 59%, its chroma 0.137 and its hue 251°. Its hue sits on the cool side of the wheel. The nearest named color is Water Blue (#0E87CC), ΔE 0.023 away. Black text reads best on it, at 5.10:1.
| Hue family | Blues |
| Lightness | medium-dark (59%) |
| Chroma | moderately saturated (0.137) |
| Temperature | cool |
| Nearest name | Water Blue (#0E87CC) |
| Black text | 5.10:1 |
| White text | 4.11:1 |
Values
| HEX | #3580CB |
| RGB | rgb(53, 128, 203) |
| HSL | hsl(210, 59%, 50%) |
| OKLCH | oklch(59% 0.137 251.3) |
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 #3580CB | 4.11:1 | AA large text | Lc -73.4 | Content text, not long reading |
| Black text on #3580CB | 5.10:1 | AA | Lc 36.1 | Non-text elements, placeholder text |
| #3580CB text on white | 4.11:1 | AA large text | Lc 67.9 | Content text, not long reading |
| #3580CB text on black | 5.10:1 | AA | Lc -33.7 | 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
#F2F6FB
oklch(97.2% 0.008 253.9)
-
Step 100
100
#E1EBF6
oklch(93.6% 0.018 250.6)
-
Step 200
200
#C9DBF0
oklch(88.4% 0.035 252.3)
-
Step 300
300
#A4C4E8
oklch(80.9% 0.062 251.6)
-
Step 400
400
#72A5DC
oklch(70.8% 0.098 251.1)
-
Step 500
500
#4A8DD3
oklch(63.1% 0.126 251.4)
-
Step 600
600 (this color)
#3580CB
oklch(59% 0.137 251.3)
-
Step 700
700
#1B63A6
oklch(49.2% 0.127 251.1)
-
Step 800
800
#1A5186
oklch(42.8% 0.105 251.1)
-
Step 900
900
#1C436B
oklch(37.6% 0.082 251.4)
-
Step 950
950
#11283F
oklch(27.1% 0.052 250.3)
#3580CB 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) | #5D85CE | 0.042 |
| Deuteranopia (no green cones) | #4777CA | 0.026 |
| Tritanopia (no blue cones) | #00929C | 0.103 |
| Achromatopsia (no color) | #7D7D7D | 0.137 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3580CB
#3580CB
oklch(59% 0.137 251.3)
- #AB6E00
#AB6E00
oklch(58.9% 0.127 71.3)
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 #3580CB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Water Blue #0E87CC ΔE 0.023
- Windows Blue #3778BF ΔE 0.026
- Cool Blue #4984B8 ΔE 0.037
- Steel Blue #4682B4 ΔE 0.039
- Nice Blue #107AB0 ΔE 0.050
- Dark Sky Blue #448EE4 ΔE 0.053
- Blue NCS #118AB2 ΔE 0.056
- Off Blue #5684AE ΔE 0.056
Use #3580CB 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.