iPhone app - Saving default colours for text etc.

 I'm very new to Premier Rush and I'm figuring it all out along the way. Probably a very silly question but how do you go about saving a colour to the row where I've popped a blue arrow. I'd like to be able to quickly use the shades I use frequently. I'm using it on my iPhone and can't figure out how to save them.  Many thanks 🙂