.block {
        background-image:url('stripes.png');
}
.filter {
        background-image:url('stripes-yellow.png');
}
.canvas {
	background:none;
}
.source {
	background-image:url('stripes-red.png');
}
.sink {
        background-image:url('stripes-green.png');
}
.decision {
	background-image:url('stripes-blue.png');
}