[Users] Color schemes

[John Jason Jordan]

I have Claws Mail 3.8.1 on Mint x86_64. Normally I use my laptop for
e-mail (also Claws Mail, Fedora x86_64), but the laptop networking died
(don't ask - a very long and amazingly stupid story), so now I have to
use Claws Mail on my desktop. I used a thumb drive to copy the Claws
Mail configuration and mailboxes from the laptop to the desktop. All is
well, except when a message is highlighted in the Inbox, or when a
mailbox is highlighted, the background changes from white to dark blue.
The text is black, Black text on a dark blue background is impossible
to read. 

I went into Preferences > Display > Colors, but there seems to be no
way to change the background color. That is, I changed some of the
colors and some of the settings in the Other tab, but the background
color remains dark blue. I also tried different themes, but also to no
avail. 

Can someone tell me how to change the background color of a selection?