in Moodle 2.2! The MyMobile theme is custom-designed for smartphone browser screens.
It is recommended that the MyMobile theme is selected as the theme for mobile devices in Settings > Site administration > Appearance > Themes > Theme selector.
Site administration settings
An administrator can toggle the colour swatch of the theme between grey and light/blue and change other theme settings in Settings > Site administration > Appearance > Themes > MyMobile.