If you set a colour on the lookAndFeel, it will have an effect for all components using that LookAndFeel.
getLookAndFeel().setColour (Slider::thumbColourId, Colours::red);
will change all slider’s thumb to red, if they use that LookAndFeel.
If a Component doesn’t have it’s own LookAndFeel, it will use the parent’s one. So this kind of inheritance is already happening.
The colours you set directly on a Component is only used for that particular Component.
OT: I wanted designers to be able to create all the layout and colour schemes for my plugins, thats why I wrote this module, that lets you design your plugin, and it uses the CSS paradigm for colouring and other style effects (borders, captions, margins, etc.)
Maybe that is an alternative…
