a {
color: hsl(0, 0%, 0%);
}
b {
color: hsl(120, 100%, 50%);
c {
color: hsl(360, 100%, 50%);
d {
color: hsl(-314.159, 50%, 50%);
e {
color: hsl(0, 0%, 0%, 0.5);
f {
color: hsl(1, 2, 3);