If you are in need to change the design of the card component, you can do that using a little bit of CSS code.
<style>
.card-container > .card {
background: transparent !important;
}
.light .card-group .card {
border: var(--field-border-width) transparent;
</style>
This code above will remove the background and the border around the options of the card component for you.
If you would like to change their color instead, you can do that by changing the word "transparent" in the code to the HEX color code of your choice.