Hi.
We have a RGB selector, but, we have not a RGBA selector. Some actions require select the alpha, so, a new selector RGBA could be useful to avoid use rgb+number.
What devices support opacity then? Or what kind of entity would use the rgba selector for its state? Without an entity that has something rgba, the selector would not show up anywhere.
The actions are not only for devices.
In my case, I need it for select the filament color of my 3D printer (bambulab).
Ah, ok. That makes sense. The action is for a device though, an extruder. I have transparent filament too, just no way to mix it 
The entity problem is a thing too though. You can have a selector, but there’s no entity for rgba colors, and also no good way to display the value. So a number with a slider for opacity is currently your only option that makes sense in the UI.
The problem is that API expect a RGBA color, so, the component need combine the two fields.
By other hand, for the user is more clean only use a selector.