Allow to_color to work with Cycled(n::Int)

[Datseris]

Not much more to say here, it would make themeing and UX much more pleasant if I could just get the color of the cycled as an actual RGBf color, as many things that dispatch on RGB don't dispatch on Cycled. cgrad for example.

[jkrumbiegel]

the problem here is that Cycled looks up the value in the cycler of an axis during plotting, so it's not stateless. Maybe we can redesign so Cycled computes the values directly from the theme

[Datseris]

Computing values during the cycling and being state dependent is fine for Cycled(). However, here I am talking specifically about Cycled(n::Int), which is stateless (or rather, should be, as I thought Cycled(n::Int) means n-th color of the theme cycle).

[jkrumbiegel]

it is currently implemented Axis-theme-dependent, so you cannot call it without one. We could maybe make it only theme-dependent.

[Datseris]

We could maybe make it only theme-dependent.

Yes, that makes the most sense for Cycled(n::Int) because users that theme their own colors would typically want to use them also outside the axis cycling features (like in my case here).