WPF animation - running multiple animations

When you are contemplating animations in WPF, you can have more than one running at any particular time.
Remember though, that each one creates a whole gamut of objects in order to run that animation.

Here is an example of how to change the width of a rectangle and also change the colour halfway through the width animation.
To start the animation, you need to click on the rectangle:

Notice how the animation is held at the end.