How to theme on Angular portal for 9.0.3 LTS

I am using an 9.0.3LTS installation of OneIdentity.  I have started the migration to Angular portal.  However, how do you theme the installations, ie change colours, fonts etc.  It appears that starting in 9.2 there is a custom_theme that you can do.  However, I do not see this in 9.0.  Is this correct.

So, questions:

1. How do you change the colours etc of the portal

2. Can this be done for each separate API Web portal, or is it universal.