Fix crash on rendering card with no header colour

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## v1.2.0 (2020-11-17)
+
+Changes:
+
+- Add swiping between groups on the home screen
+- Fix crash with cards lacking header colour
+
 ## v1.1.0 (2020-11-11)
 
 Changes:

app/src/main/java/protect/card_locker/Utils.java

@@ -16,6 +16,10 @@ public class Utils {
         int tileLetterFontSize = context.getResources().getDimensionPixelSize(R.dimen.tileLetterFontSize);
         int pixelSize = context.getResources().getDimensionPixelSize(R.dimen.cardThumbnailSize);
 
+        if (backgroundColor == null) {
+            backgroundColor = LetterBitmap.getDefaultColor(context, store);
+        }
+
         return new LetterBitmap(context, store, store,
                 tileLetterFontSize, pixelSize, pixelSize, backgroundColor, needsDarkForeground(backgroundColor) ? Color.BLACK : Color.WHITE);
     }