Color property name changes `R` to `Red`

[mattleibow]

The Color.R -> Color.Red is not super different as I am not sure how many people actually use the components individually. However, this may be different enough.

But, it is worth pointing out that it is different and it is also different to most other Microsoft color types out there (WPF, UWP, WinUI, WinForms, Xamarin.Forms).

iOS does not have this and they have a GetRGBA(out r, out g, out b, out a)

Relates to parent issue: #58

[hartez]

I personally prefer the full names, and the full names fit more closely with the framework naming guidelines.

That said, for folks making the transition from System.Drawing, Xamarin.Forms, Windows.UI.Color, etc., this might be a small and annoying hiccup.

Since we're talking about readonly fields, we could simply add property accessors with the short names:

public float R => Red;
public float G => Green;
public float B => Blue;
public float A => Alpha;

[Redth]

Done.