The fill-opacity CSS property defines the opacity of the painting operation (color, gradient, pattern, etc.) applied to SVG shapes or text content elements to fill the element. The property defines the opacity of the element's fill only; it does not affect the stroke. If present, it overrides the element's fill-opacity attribute....only applies to <circle> , <ellipse> , <path> , <polygon> , <polyline>...r="20" fill-opacity="1" /> <ellipse cx="75" cy="75" rx="20" ry="10"...