导航栏按钮图片颜色与设置的图片不一致

翻新老项目时，出现导航栏按钮图片颜色与设置的图片不一致情况，处理方法如下：

self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithImage:loadImageByName(@"icon") style:UIBarButtonItemStyleDone target:self action:@selector(rightSetting:)];

    [self.navigationItem.rightBarButtonItem setImage:[loadImageByName(@"icon") imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];