Bit of cleanup

tools/editor/texture/texture.js

@@ -164,8 +164,9 @@ function applyImageData(width, height, data, filename, formatLabel, format) {
 
   // Sync format selector when loading an existing DTF
   if (format !== undefined) {
-    state.format       = format;
-    formatSelect.value = format;
+    state.format         = format;
+    formatSelect.value   = format;
+    redAsAlphaRow.hidden = format !== DTF.FORMAT_ALPHA;
   }
 
   // Sidebar info