Qt addr/utxo lists: in dark theme, fix item bgcolor (was pure black)

regression from e362d1aac4

electrum/gui/qt/address_list.py

@@ -236,8 +236,8 @@ class AddressList(MyTreeView):
         address_item[self.Columns.COIN_BALANCE].setData(balance, self.ROLE_SORT_ORDER)
         address_item[self.Columns.FIAT_BALANCE].setText(fiat_balance_str)
         address_item[self.Columns.NUM_TXS].setText("%d"%num)
-        c = ColorScheme.BLUE if self.wallet.is_frozen_address(address) else ColorScheme.DEFAULT
-        address_item[self.Columns.ADDRESS].setBackground(c.as_color(True))
+        c = ColorScheme.BLUE.as_color(True) if self.wallet.is_frozen_address(address) else self._default_bg_brush
+        address_item[self.Columns.ADDRESS].setBackground(c)
 
     def create_menu(self, position):
         from electrum.wallet import Multisig_Wallet

electrum/gui/qt/util.py

@@ -592,6 +592,8 @@ class MyTreeView(QTreeView):
         self._pending_update = False
         self._forced_update = False
 
+        self._default_bg_brush = QStandardItem().background()
+
     def set_editability(self, items):
         for idx, i in enumerate(items):
             i.setEditable(idx in self.editable_columns)

electrum/gui/qt/utxo_list.py

@@ -125,7 +125,7 @@ class UTXOList(MyTreeView):
             color = ColorScheme.GREEN.as_color(True)
         else:
             tooltip = key
-            color = ColorScheme.DEFAULT.as_color(True)
+            color = self._default_bg_brush
         for col in utxo_item:
             col.setBackground(color)
             col.setToolTip(tooltip)