[UITabBar appearance].barStyle = UIBarStyleDefault;
    [self.tabBar setBackgroundColor:[UIColor blueColor]];

    //设置字体颜色
    // 适配iOS13
    if (@available(iOS 13.0, *)) {
        // iOS13 及以上
        self.tabBar.tintColor = [UIColor redColor];
        self.tabBar.unselectedItemTintColor = [UIColor yellowColor];
    }
    else {
        // iOS13 以下
        UITabBarItem *item = [UITabBarItem appearance];
        NSMutableDictionary *attrNor = [NSMutableDictionary dictionary];
        attrNor[NSForegroundColorAttributeName] = [UIColor redColor];
        [[UITabBarItem appearance] setTitleTextAttributes:attrNor forState:UIControlStateNormal];
        
        NSMutableDictionary *attrSel = [NSMutableDictionary dictionary];
        attrSel[NSForegroundColorAttributeName] = [UIColor blueColor];
        [[UITabBarItem appearance] setTitleTextAttributes:attrSel forState:UIControlStateSelected];
    }

注意如果展现的icon和UI图不符，记得设置图片展示模式

VC.tabBarItem.image = [[LSMHelper imageNamed:@"livesteam_square"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]