Thunderbird
Change the selected row color
create a file named userChrome.css in the directory
$HOME/.thunderbird/{profile_dir}/chrome
With following content (replace #FFD445 and #000000 with your favored color):
@namespace url("[http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul](http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul)");
#threadTree treechildren::-moz-tree-row(selected) {
background-color: #FFD445 !important;
}
#threadTree treechildren:-moz-tree-cell-text(selected) {
color: #000000 !important;
}