Hey thank you everyone.
I must have had a typo when I initially posted this - but it seems to work now.
Notes: I used ui.parse_color('blue').CGColor()
This works with RGBA, Hex and Named Colors.
Ill post the code when done, I am using this to create custom button styles, along with some custom styles for "checkbox" functionality (circles, squares, stars, etc)
Thanks again for your help!