style.css

#submit-button0,
#submit-button1,
#submit-button2,
#submit-button3 {
  background: rgba(0, 67, 143, 0.9);
  color: rgb(213, 231, 255);
  border-color: rgb(0, 63, 136);
}

#clear-button0,
#clear-button1,
#clear-button2,
#clear-button3 {
  background: rgba(165, 47, 47, 0.9);
  color: rgb(255, 226, 226);
  border-color: rgb(145, 0, 0);
}