If you follow the rules you can do this to maintain the theme of your app and the theme of the phone:
https://stackoverflow.com/a/9681744/628447
Other posibility is use this incredible page to make all your views
http://android-holo-colors.com/
(take a look of the main page http://android-ui-utils.googlecode.com/hg/asset-studio/dist/index.html and all of the tools)
And the best solution is use this library:
https://github.com/Prototik/HoloEverywhere