Canvas with theme

Question

I added a canvas with my project theme set to zen.
How can I change the backg of the canvas? I search but there is no file for canvas in the sdk of the theme, what it´s using this object?
Thank you, and sory for the question

Answer 1

Theming Document
1.   Create skinning for all the components in flex using Flash Catalyst 5.5.
(Flash Catalyst  Learning aid : http://tv.adobe.com/show/flash-catalyst-1-1-with-doug-winnie)
2.   Use them in a model application using CSS.
Eg. of CSS:
/* CSS file */
@namespace s "library://ns.adobe.com/flex/spark";
@namespace mx "library://ns.adobe.com/flex/mx";
s|Button {
      fontSize:24; //may or may not use these
      color: #FF9933;
      skinClass: ClassReference("ButtonSkin3");
      cornerRadius:10;
Where ButtonSkin3 is the Skinning file… in same folder where the CSS file exists.
3.   After that model is finalized place the CSS in your Application (Right Click on the CSS and check CSS to SWF) using flash builder.
4.   Use the SWF file for your application to change the look and feel via a menu at runtime…
To learn how to do so use this link…
http://help.adobe.com/en_US/flex/using/WS2db454920e96a9e51e63e3d11c0bf69084-7f8c.html#WS2d b454920e96a9e51e63e3d11c0bf62883-7fd4
5.   In your application just call this dynamically from a menu or button.
styleManager.loadStyleDeclarations("assets/BasicStyles.swf")
BasicStyles.swf is our css file in swf format.