fpspreadsheet: Avoid TsWorkbookChartSource ignoring series color.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@3875 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/fpspreadsheet/fpspreadsheetchart.pas

@@ -365,6 +365,7 @@ var
 begin
   GetXYItem(rngX, AIndex, FCurItem.X, FCurItem.Text);
   GetXYItem(rngY, AIndex, FCurItem.Y, dummy);
+  FCurItem.Color := clDefault;
   Result := @FCurItem;
 end;