Adding alpha value to brush strokes

[aaron-dees]

When working with brush strokes, it would be nice to add the alpha value as well when setting the colour.

You can achieve a similar affect by using pressure, but it may also be useful to have the alpha value set in brush.set, or brush.stroke. Currently it looks like the alpha is ignored.

Would it be possible to add capability of passing alpha values to these functions?

Thanks

[acamposuribe]

Hey @aaron-dees,
I've also considered this as I keep using the library. Will come back to you when/if I implement it!