We've created a custom theme that changes the background colors of the tabs, but selected and unselected. This has worked well in 4.7. After upgrading, we've found that our custom theme still works well besides for the background color of the selected tab - it is now white instead of green as stated in our theme. Inspecting the styles, we've found that there is now the following bit that seems to be on the form itself (not from CSS) so it always takes prededence over anything in our custom CSS:

.theme-entry .tab-box ul.tab-box-tabs a.tab.selected .tab-wrapper {
    background-color: #FFFFFF !important;
}

Is there any to get rid of this? I've hunted through all css files in the SmartForms runtime folder but cannot find where this is coming from.