Hello There,
Thanks for writing in!
You can add this under Custom > CSS in the Customizer:
.x-accordion-group:nth-child(1) .x-accordion-heading .x-accordion-toggle.collapsed {
color: #fff !important;
background-color: #cdbebe;
}
.x-accordion-group:nth-child(2) .x-accordion-heading .x-accordion-toggle.collapsed {
color: #fff !important;
background-color: #775454;
}
.x-accordion-group:nth-child(3) .x-accordion-heading .x-accordion-toggle.collapsed {
color: #fff !important;
background-color: #561919;
}
Thanks.