It would be great to add a new “Number” type of property to components, that allows to control dimensions, opacity,…
And a color property, that allows to easily change the color of elements inside of the components. When you select the component instance, changing a color using “Selection colors” affects all nested elements carrying that color. A property would allow granular control of specific elements in the instance.
That would be totally great. However, its usage can be tricky. I think we need to define the problem first. creating a “theme” for the whole page would be great. but at last, we need to show all variants to the client/programmer in one package. so, all the states of a component like buttons should be visible as one component (like primary, secondary or enable, hover, etc).
changing selection colors would also do the same trick to make different types of buttons. and also would take the same time.
So, based on this, I’ll assume that you need a global “theme” to change all of the borders or colors in one move. am I right? I’ll be glad if you describe your need more. the more we define our needs, the easier we can have it.
However your suggestion sounds more like expanding global styles to other things than colors, text, effects and grids, which is definitely needed as well (ex: global corner radius styles). I think the forum already has such requests.
What you describe can already be achieved with global color styles (ex: “Borders/Red”) unless I misunderstood.