body {
	margin: 0;
}
svg {
	width: 100%;
	height: 80vh;
}
path {
	vector-effect: non-scaling-stroke;
}
path.country {
	fill: #ccc;
}
path.country.no-data {
	opacity: .3;
}
path.schengen {
	fill: none;
	stroke: #999;
	stroke-width: 2;
}
path.border {
	fill: none;
	stroke: #fff;
	stroke-width: 1;
}
circle {
	vector-effect: non-scaling-stroke;
}
circle.metric {
	fill: none;
	stroke: rgba(0, 0, 0, .3);
	stroke-width: 2;
}
circle.application-count {
	fill: #f00;
}
body {
	margin: 0;
}
svg {
	width: 100%;
	height: 80vh;
}
path {
	vector-effect: non-scaling-stroke;
}
.country {
	fill: #ccc;
}
.country.no-data {
	opacity: .3;
}
path.schengen {
	fill: none;
	stroke: #999;
	stroke-width: 2;
}
path.border {
	fill: none;
	stroke: #fff;
	stroke-width: 1;
}
circle {
	vector-effect: non-scaling-stroke;
}
circle.metric {
	fill: none;
	stroke-width: 1;
	mix-blend-mode: difference;
	stroke: rgba(255, 255, 255, .5);
}
circle.application-count {
	mix-blend-mode: multiply;
	fill: #415A77;
}
Change colours and use mix-blend-mode
Change colours and use mix-blend-mode
