Changing a background's pattern

[Joshua Choi]

How may I change a background's pattern? For instance, here's an ideal
example if something like Background#pattern= worked.

  Shoes.app do
    @background = background white
    button 'Blue' { @background.pattern = blue }
    button 'Yellow' { @background.pattern = yellow }
  end

In other words, dynamic backgrounds. Is it possible, or could it
please be implemented in the future?

Joshua Choi