Storyline Custom Theme Colors
I find creating custom color themes to be very confusing in Storyline. It's easier to pick a default theme, and change the colors as needed to meet a clients palette.
What might be a better way to define a custom color theme, is to draw and style objects on a slide and have Storyline create the theme based on how those objects are styled. To my knowledge, that functionality doesn't currently exist, but it sure would make life easier creating custom color themes.
Just a thought.