I think you need something like an animation system.
You alway can acces almost every parameter via script -> get_node().set_param(value)
than you can use a for loop to do whatever you need..
But Godot's animation system is awsome and you should give it a try. Just add an animationplayerNode
Than a toolbar at the bottom will appear: click on the new Icon, and you are ready to go.
There now should be an Key icon next to every parameter in the Editor. just click on it. Go some frames further in the animation bar, change the value and click the same Key again...
Than you can acces the animation with the animationplayenode:
In your scripts:
get_node("/root/Animationplayer").play("animationname")
This system is really powerful because you really can animate anything. colors,positions,opacity,even custom values you exported from your script...
Which makes it possible to animate any property of your own custom objects...