サイドバー自分はこれ

/* ブックマーク・履歴文字大きさ */
#bookmarksPanel, #history-panel {
font-size: 10pt !important;
}

/* ブックマーク・マウスオーバー時の文字色（太字）と背景色 */
#bookmarks-view treechildren::-moz-tree-cell-text(hover) {font-weight: bold;color: blue !important;}
#bookmarks-view treechildren::-moz-tree-cell(hover) {background-color: #999 !important;}

/* ブックマーク選択時の文字色（太字）と背景色 */
#bookmarksPanel treechildren::-moz-tree-cell-text(selected) {
font-weight: bold !important; color: white !important;}
#bookmarksPanel treechildren::-moz-tree-row(selected) {background-color: #0040d6 !important;}


/* 履歴・マウスオーバー時の文字色（太字）と背景色 */
#historyTree treechildren::-moz-tree-cell-text(hover) {font-weight: bold;color: blue !important;}
#historyTree treechildren::-moz-tree-cell(hover) {background-color: #999 !important;}

/* 履歴選択時の文字色（太字）と背景色 */
#historyTree treechildren::-moz-tree-cell-text(selected) {
font-weight: bold !important; color: white !important;}
#historyTree treechildren::-moz-tree-row(selected) {background-color: #0040d6 !important;}