title: TextButton change text color on button down?
body: <p>How can I change the text color of a button when I am over it, pressing it or having it cancelled out?</p>
  
  <pre><code>com.badlogic.gdx.scenes.scene2d.ui.TextButton$TextButtonStyle: {
          default: { down: round-down, up: round, font: default-font },
      },
  </code></pre>
  
  <p>Here I can set the default buttons texture on down, up etc and the font used for all. I want the button to change the font color or the font as a whole for each different state. Is this possible within the skin's json file?</p>
  
  <p>I know how to create this programmatically with ui styles. I just like the convenience of having it in the skin.</p>