div[data-testid*="test-tiles"] button[aria-label="Primary"].tiles {
background-color: gold;
}
div[data-testid*="test-tiles"] button[aria-label="Secondary"].tiles {
background-color: green;
color: white;
}
div[data-testid*="test-tiles"] button[aria-label="Go!"].tiles {
background-color: magenta;
color: white;
}
The custom CSS class here is “test-tiles”.
If you have a sole “open link” action, it should change from “button[aria-label…]” to “a[aria-label…”.