use folder-close-alt without highlighting

discussion of this happened in  #5584

IPython/html/static/style/style.min.css

@@ -1,3 +1,7 b''
+.clearfix{*zoom:1}.clearfix:before,.clearfix:after{display:table;content:"";line-height:0}
+.clearfix:after{clear:both}
+.hide-text{font:0/0 a;color:transparent;text-shadow:none;background-color:transparent;border:0}
+.input-block-level{display:block;width:100%;min-height:30px;-webkit-box-sizing:border-box;-moz-box-sizing:border-box;box-sizing:border-box}
 article,aside,details,figcaption,figure,footer,header,hgroup,nav,section{display:block}
 audio,canvas,video{display:inline-block;*display:inline;*zoom:1}
 audio:not([controls]){display:none}
@@ -852,10 +856,6 b' a.label:hover,a.label:focus,a.badge:hover,a.badge:focus{color:#fff;text-decorati'
 .show{display:block}
 .invisible{visibility:hidden}
 .affix{position:fixed}
-.clearfix{*zoom:1}.clearfix:before,.clearfix:after{display:table;content:"";line-height:0}
-.clearfix:after{clear:both}
-.hide-text{font:0/0 a;color:transparent;text-shadow:none;background-color:transparent;border:0}
-.input-block-level{display:block;width:100%;min-height:30px;-webkit-box-sizing:border-box;-moz-box-sizing:border-box;box-sizing:border-box}
 @-ms-viewport{width:device-width}.hidden{display:none;visibility:hidden}
 .visible-phone{display:none !important}
 .visible-tablet{display:none !important}
@@ -1329,7 +1329,7 b' input.nbname_input,input.engine_num_input{padding-top:3px;padding-bottom:3px;hei'
 input.engine_num_input{width:60px}
 .highlight_text{color:#00f}
 #project_name>.breadcrumb{padding:0;margin-bottom:0;background-color:transparent;font-weight:bold}
-.folder_icon:before{color:#08c;font-family:FontAwesome;font-weight:normal;font-style:normal;text-decoration:inherit;-webkit-font-smoothing:antialiased;*margin-right:.3em;content:"\f07c"}
+.folder_icon:before{font-family:FontAwesome;font-weight:normal;font-style:normal;text-decoration:inherit;-webkit-font-smoothing:antialiased;*margin-right:.3em;content:"\f114"}
 .notebook_icon:before{font-family:FontAwesome;font-weight:normal;font-style:normal;text-decoration:inherit;-webkit-font-smoothing:antialiased;*margin-right:.3em;content:"\f02d"}
 .ansibold{font-weight:bold}
 .ansiblack{color:#000}

IPython/html/static/tree/less/tree.less

@@ -128,8 +128,7 b' input.engine_num_input {'
 }
 
 .folder_icon:before {
-    color: #08c;
-    .icon(@folder-open)
+    .icon(@folder-close-alt)
 }
 
 .notebook_icon:before {