Button background setting

This question is almost embarrassing to ask, but I can't find the answer in any documentation.

I have a UIButton in a view. In IB, I set the button's background to a colour. The original rectangle in the Identity Inspector shows a half-black, half-white rectangle for the button's background.

I can't find anyway to set the backgro开发者_如何转开发und back to the original setting. Anybody know how to do this?

Thanks in advance for any help.

John Doner

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Half black, half white means it has an alpha value.

Click on the color, and in the bottom part of the color picker, you can set the alpha. Set it back to 0% to have the original value back.