fix custom blink patter background on Android 2.3

I realised in the 2.3 emulator, that the background while chosing the custom led blink pattern is wrong. There is dark text on a black background.

Before and after the patch screenshots:
![before patch 2 3](https://f.cloud.github.com/assets/5296073/2467546/03f19646-afc1-11e3-9755-737753ba3639.jpg) ![after patch 2 3](https://f.cloud.github.com/assets/5296073/2467547/08e76f9a-afc1-11e3-945d-d6e75cb50c42.jpg)