How do you style DataTable Dropdown with CSS?

How do you do custom css styling to the dropdown in a DataTable? I tried this but it doesn’t really have much of an important when it comes to visually change the style to the drop down:

.Select-menu-outer {
  overflow-y: visible !important;
  overflow-x: visible !important;
  color: black !important;
  display: grid !important;
  z-index: 500 !important;