fixes #13. that is the current behavior in bootstrap but cerulean is now overriding it.

cerulean/bootstrap.css

@@ -3164,7 +3164,7 @@ input[type="submit"].btn.btn-mini {
 .navbar .nav .active > a:hover {
   color: #ffffff;
   text-decoration: none;
-  background-color: #369bd7;
+  background-color: rgba(0, 0, 0, 0.2);
 }
 .navbar .divider-vertical {
   height: 40px;
@@ -4190,9 +4190,8 @@ a.badge:hover {
   background-repeat: no-repeat;
   filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#369bd7', endColorstr='#61b0df', GradientType=0);
 }
-.navbar .nav .active > a,
-.navbar .nav .active > a:hover {
-  background-color: #369bd7;
+.navbar .nav li.dropdown.active > .dropdown-toggle,
+.navbar .nav li.dropdown.active.open > .dropdown-toggle {
   background-color: rgba(0, 0, 0, 0.2);
 }
 .navbar .search-query {

cerulean/bootstrap.min.css

@@ -574,7 +574,7 @@ button.btn.btn-mini,input[type="submit"].btn.btn-mini{*padding-top:1px;*padding-
 .navbar .btn{display:inline-block;padding:4px 10px 4px;margin:5px 5px 6px;line-height:18px;}
 .navbar .btn-group{margin:0;padding:5px 5px 6px;}
 .navbar .nav>li>a:hover{background-color:transparent;color:#ffffff;text-decoration:none;}
-.navbar .nav .active>a,.navbar .nav .active>a:hover{color:#ffffff;text-decoration:none;background-color:#369bd7;}
+.navbar .nav .active>a,.navbar .nav .active>a:hover{color:#ffffff;text-decoration:none;background-color:rgba(0, 0, 0, 0.2);}
 .navbar .divider-vertical{height:40px;width:1px;margin:0 9px;overflow:hidden;background-color:#369bd7;border-right:1px solid #61b0df;}
 .navbar .nav.pull-right{margin-left:10px;margin-right:0;}
 .navbar .btn-navbar{display:none;float:right;padding:7px 10px;margin-left:5px;margin-right:5px;background-color:#50a8dc;background-image:-moz-linear-gradient(top, #61b0df, #369bd7);background-image:-ms-linear-gradient(top, #61b0df, #369bd7);background-image:-webkit-gradient(linear, 0 0, 0 100%, from(#61b0df), to(#369bd7));background-image:-webkit-linear-gradient(top, #61b0df, #369bd7);background-image:-o-linear-gradient(top, #61b0df, #369bd7);background-image:linear-gradient(top, #61b0df, #369bd7);background-repeat:repeat-x;filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#61b0df', endColorstr='#369bd7', GradientType=0);border-color:#369bd7 #369bd7 #2071a1;border-color:rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.1) rgba(0, 0, 0, 0.25);*background-color:#369bd7;filter:progid:DXImageTransform.Microsoft.gradient(enabled = false);-webkit-box-shadow:inset 0 1px 0 rgba(255,255,255,.1), 0 1px 0 rgba(255,255,255,.075);-moz-box-shadow:inset 0 1px 0 rgba(255,255,255,.1), 0 1px 0 rgba(255,255,255,.075);box-shadow:inset 0 1px 0 rgba(255,255,255,.1), 0 1px 0 rgba(255,255,255,.075);}.navbar .btn-navbar:hover,.navbar .btn-navbar:active,.navbar .btn-navbar.active,.navbar .btn-navbar.disabled,.navbar .btn-navbar[disabled]{background-color:#369bd7;*background-color:#288ecb;}
@@ -716,7 +716,7 @@ a.label:hover,a.badge:hover{color:#ffffff;text-decoration:none;cursor:pointer;}
 .invisible{visibility:hidden;}
 .navbar,.subnav{font-family:'Telex',sans-serif;}
 .navbar-inner{background-color:#3f9fd9;background-image:-webkit-gradient(linear, 0 0, 0 100%, from(#369bd7), color-stop(90%, #369bd7), to(#61b0df));background-image:-webkit-linear-gradient(#369bd7, #369bd7 90%, #61b0df);background-image:-moz-linear-gradient(top, #369bd7, #369bd7 90%, #61b0df);background-image:-ms-linear-gradient(#369bd7, #369bd7 90%, #61b0df);background-image:-o-linear-gradient(#369bd7, #369bd7 90%, #61b0df);background-image:linear-gradient(#369bd7, #369bd7 90%, #61b0df);background-repeat:no-repeat;filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#369bd7', endColorstr='#61b0df', GradientType=0);}
-.navbar .nav .active>a,.navbar .nav .active>a:hover{background-color:#369bd7;background-color:rgba(0, 0, 0, 0.2);}
+.navbar .nav li.dropdown.active>.dropdown-toggle,.navbar .nav li.dropdown.active.open>.dropdown-toggle{background-color:rgba(0, 0, 0, 0.2);}
 .navbar .search-query{border:1px solid #2480b6;}
 .navbar .nav-collapse.in>.nav>li .dropdown-menu a{color:#ffffff;}.navbar .nav-collapse.in>.nav>li .dropdown-menu a:hover{color:#ffffff;}
 .navbar .nav-collapse.in .nav li>a{color:#ffffff;}.navbar .nav-collapse.in .nav li>a:hover{background-color:#2B7CAC;}

cerulean/bootswatch.less

@@ -19,11 +19,10 @@
   #gradient > .vertical-three-colors(@navbarBackground, @navbarBackground, 90%, @navbarBackgroundHighlight);
 }
 
-.navbar .nav .active > a,
-.navbar .nav .active > a:hover {
-  background-color: @navbarBackground;
-  background-color: rgba(0,0,0,.2);
-}
+	.nav li.dropdown.active > .dropdown-toggle,
+	.nav li.dropdown.active.open > .dropdown-toggle {
+		background-color: @navbarLinkBackgroundActive;
+	}
 
 .navbar .search-query {
 	border: 1px solid darken(@linkColor, 10%);

cerulean/variables.less

@@ -153,7 +153,7 @@
 @navbarLinkColorHover:            @white;
 @navbarLinkColorActive:           @navbarLinkColorHover;
 @navbarLinkBackgroundHover:       transparent;
-@navbarLinkBackgroundActive:      @navbarBackground;
+@navbarLinkBackgroundActive:      rgba(0,0,0,.2);
 
 @navbarSearchBackground:          lighten(@navbarBackground, 25%);
 @navbarSearchBackgroundFocus:     @white;