iOS 7 - 禁用UITabBarItem色调

我有一个带有五个图标的UITabBar，其中大多数只有一种颜色是扁平的。但是，其中一个按钮不应该有浅色，因为它是公司的徽标，徽标有各种不同的颜色。我知道有可能使用UINavigationBar和UIToolbar（这是我正在使用的，这是一个可怕的解决方法）。

I have a UITabBar with five icons, most of them being flat with just one color. However, one of these buttons should not have a tint color, since it's the company's logo and the logo has various different colors. I know it's possible to to so with UINavigationBar and UIToolbar (which is what I'm using and it's a horrible workaround).

我做了一些沉重的搜索并尝试了许多不同的解决方案（我想出了一些疯狂的解决方案），但它们似乎都不适用于iOS 7。有没有人知道如何实现这一目标？

I did some heavy searching and tried many different solutions (I came up with with some crazy ones too), but none of them seem to work for me o iOS 7. Does anyone have an idea of how to achieve that?

万分感谢！