LT-281: Replacing variables for theme calls

Packages/viewerbase/client/components/viewer/loadingIndicator/loadingIndicator.styl

@@ -1,21 +1,21 @@
 @import "{design}/app.styl"
 
 .imageViewerLoadingIndicator
-  color: $textSecondaryColor
+  theme('color', '$textSecondaryColor')
 
 .faded
   opacity: 0.5
 
 .imageViewerErrorLoadingIndicator
-  color: $uiYellow
-  
+  theme('color', '$uiYellow')
+
   p, h4
     text-align: center
     padding: 4px 0
-    
+
   p
     font-size: 11pt
-      
+
 .loadingIndicator
   display: none
   pointer-events: none // Necessary for click-through to cornerstone element below
@@ -26,11 +26,11 @@
   font-size: 18px
   z-index: 100
   background-color: rgba(0,0,0,0.75)
-  
+
   .indicatorContents
     position: absolute
     top: 40%
     width: 100%
     font-size: 30px
     font-weight: 300
-    text-align: center
+    text-align: center