Adjusted spinner color

static/css/styles.css

@@ -1565,7 +1565,7 @@ create an even border-bottom line */
 
 .spinner {
     border: 8px solid #f3f3f3;
-    border-top: 8px solid #00FFFF;
+    border-top: 8px solid black;
     border-radius: 50%;
     width: 60px;
     height: 60px;