org.eclipse.jdt/intro/css/tutorials.css

a#hello-world img { background-image : url(../../images/topiclabel/tu_javaapp48.svg); }
a#hello-world:hover img { background-image : url(../../images/topiclabel/tu_javaapp48.svg); }

a#swt img { background-image : url(../../images/topiclabel/tu_swtapp48.svg); }
a#swt:hover img { background-image : url(../../images/topiclabel/tu_swtapp48.svg); }