a {
  background-image: conic-gradient(rgb(255,255,0), rgb(0,128,0));
}

b {
  background-image: conic-gradient(rgb(255,255,0) 0, rgb(0,128,0) 100%);
}

c {
  background-image: conic-gradient(rgb(255,255,0), rgb(0,128,0));
}

d {
  background-image: conic-gradient(at left top, rgb(255,255,0), rgb(0,128,0));
}

e {
  background-image: conic-gradient(at 25% bottom, rgb(255,0,0), rgb(255,255,0), rgb(0,128,0));
}

f {
  background-image: conic-gradient(from 20deg, rgb(255,0,0), rgb(255,255,0) 50%, rgb(0,128,0));
}

g {
  background-image: conic-gradient(at 20px 20px from 0.25turn, rgb(255,0,0), rgb(255,255,0), rgb(0,128,0));
}

h {
  background-image: conic-gradient(from 20deg in oklab, rgb(255,0,0), rgb(255,255,0), rgb(0,128,0));
}

i {
  background-image: conic-gradient(in rec2020, rgb(255,0,0), rgb(255,255,0), rgb(0,128,0));
}

j {
  background-image: conic-gradient(from 10deg in hsl longer hue, rgb(255,0,0), rgb(255,255,0), rgb(0,128,0));
}

k {
  background-image: conic-gradient(at 20px 20px from -10deg, rgb(255,0,0), rgb(255,255,0));
}