So as I start putting the app together im spending more time looking at the logo and really not liking it with the 3 colours together all the time. I think it looks too "childish" so I've been playing again and decided on a full white outline with the colours coming in once selected. The purple will be the main background at the beginning of the app so this is how the logo will look most of the time:
But will also work on the other colour backgrounds:
Im much happier with this and it will make it easier to put the app icon together too.