I have solved this. For anyone who stumbles onto this I used the basic strategy from here:
But modified the themes slightly:
in values/: Theme.Black.NoTitleBar
in values-v11/: Theme.Holo
in values-v14/:Theme.DeviceDefault.NoActionBar
This allows for the darker version of the select box across Android devices. I have not managed to style them further (such as colouring the buttons etc) but I imagine you can use the Android custom theming to achieve this within the themes.xml files.