ui: apply purple theme (twi is best color)

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/DecryptFragment.java

@@ -192,7 +192,7 @@ public class DecryptFragment extends Fragment {
             mLookupKey.setVisibility(View.GONE);
 
             // successful decryption-only
-            mResultLayout.setBackgroundColor(getResources().getColor(R.color.result_blue));
+            mResultLayout.setBackgroundColor(getResources().getColor(R.color.result_purple));
             mResultText.setText(R.string.decrypt_result_decrypted);
         }
     }

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/SlidingTabStrip.java

@@ -34,7 +34,7 @@ class SlidingTabStrip extends LinearLayout {
     private static final int DEFAULT_BOTTOM_BORDER_THICKNESS_DIPS = 2;
     private static final byte DEFAULT_BOTTOM_BORDER_COLOR_ALPHA = 0x26;
     private static final int SELECTED_INDICATOR_THICKNESS_DIPS = 8;
-    private static final int DEFAULT_SELECTED_INDICATOR_COLOR = 0xFF33B5E5;
+    private static final int DEFAULT_SELECTED_INDICATOR_COLOR = 0xFFAA66CC;
 
     private static final int DEFAULT_DIVIDER_THICKNESS_DIPS = 1;
     private static final byte DEFAULT_DIVIDER_COLOR_ALPHA = 0x20;