The only (relevant) references of TRMorph is in TRCanvas >> morphClass. Here are some solutions:
- We could add a registry. Each subclass of a new TRAbstractMorph has an order, and we use the highest order. In that case, you need to load a package Trachel4DarkTheme whenever you need to use it

- We could have a method TRCanvas class>>morphClass: aTRMorphClass, and you need to execute “TRCanvas morphClass: TRDarkMorph” before enjoying its benefit. This setting could also be accessible from the Roassal World menu.

I was thinking that having a settings option might be more feasible.

Adding a checkbox to settings (Settings > Appearance probably)... "[] use dark Roassal"

this would be also be much easier to change back without the need to unload packages

and then somewhere (TRCanvas probably), on class side similarly to UITheme stored the class(name) in singleton variable. Thus changing the option in settings would just swap TRMorph for TRDarkMorph and vice versa.

To me this feels more versatile and maybe even easier to implement.

What do you think?

Peter