.foo {
	background-image: image(rgba(0, 0, 255, .5)), url("bg-image.png");
}

.foo {
	background-image: image(rgba(0, 0, 255, .5)), image(rgba(255, 0, 255, .5)), url("bg-image.png");
}

.foo {
	--image: image(red);
}

.ignore {
	background-image: image();
}

.ignore {
	background-image: image(foo bar);
}

@supports (background: image(purple)) {
	.ignore {
		background-image: image(rgba(0, 0, 255, .5)), image(rgba(255, 0, 255, .5)), url("bg-image.png");
	}
}