1.不使用系统的颜色
tabbar2.selectedImage = [[UIImage imageNamed:@"icon-bm-g"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
2.解决tabbar标题和控制器标题相同时的问题。

tabbar2.selectedImage = [[UIImage imageNamed:@"icon-bm-g"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];