.col1:hover .overlay-yellow  {
  opacity: 1;
}

.col2:hover .overlay-maroon  {
  opacity: 1;
}

.col3:hover .overlay-green  {
  opacity: 1;
}

.col4:hover .overlay-red  {
  opacity: 1;
}

.col5:hover .overlay-blue{
  opacity: 1;
}
.col6:hover .overlay-aqua{
  opacity: 1;
}