Rise 360 colour theme

Hello.

Our org has just updated its brand colours and I'm wondering how I can update the colour theme in Rise 360 to include some of these new colours.  I am only familiar with adding one custom colour to the theme palette; is there a way to add more?

Also, when selecting the Style icon within a lesson, and choosing 'Custom', how does one get a custom colour to 'stick' to the pallet? Whenever I need to update the style colour in a lesson, I have to re-enter the HEX colour each time. Is it possible to add a colour to the pallet so that it becomes part of that pallet for the entire course?

Thank you, Marion