Added more readable selection color.

theme/night.css

 /* Loosely based on the Midnight Textmate theme */
 
 .cm-s-night { background: #0a001f; color: #f8f8f8; }
-.cm-s-night div.CodeMirror-selected { background: #a8f !important; }
+.cm-s-night div.CodeMirror-selected { background: #447 !important; }
 .cm-s-night .CodeMirror-gutter { background: #0a001f; border-right: 1px solid #aaa; }
 .cm-s-night .CodeMirror-gutter-text { color: #f8f8f8; }
 .cm-s-night .CodeMirror-cursor { border-left: 1px solid white !important; }