Manifest Files

Can you use manifest files to change the way your application looks? I don't mean that I want to make it XP or Vista style. I mean really change the look of it. (Change window border and caption design/color, button design, scroll bar design, etc.)

Thanks.

No, the manifest can only change what version of Common Controls your app should link to.

Is there a way for me to do what I want without having to create canvases?

There is, but it is not an easy task ;)

This is Windows specific:
You can Override the drawing of most parts of A Window via the WndFunc, but that is time consuming and error prone.
And you can also use the XP Theme Engine to draw your controls , but you still need to know about win32 internals.

You might be better off just making your own gui via a canvas.

Btw, there are tools that hook into your app and "skin" it for you, like WindowBlinds, or ShellWM (the latter is open source, so might be worth a look)