differentiate course number from course title on courses pages

lms/static/sass/shared/_course_object.scss

@@ -138,7 +138,7 @@
             top: 0px;
 
             h2 {
-              color: $base-font-color;
+              color: $link-color;
               display: table-cell;
               font-family: $sans-serif;
               font-size: 0.8em;
@@ -153,6 +153,7 @@
               vertical-align: middle;
 
               .course-number {
+                color: $base-font-color;
                 font-weight: 700;
                 text-transform: none;
               }

lms/templates/course.html

@@ -14,7 +14,7 @@ from courseware.courses import course_image_url, get_course_about_section
   <div class="inner-wrapper">
       <header class="course-preview">
         <hgroup>
-          <h2><span class="course-number">${course.display_number_with_default | h}</span> ${get_course_about_section(course, 'title')}</h2>
+          <h2><span class="course-number">${course.display_number_with_default | h}:</span> ${get_course_about_section(course, 'title')}</h2>
         </hgroup>
         <div class="info-link">&#x2794;</div>
       </header>