Regarding the Large Album view in Now Playing Mode

[alti0204]

the "Large Album" view shows the album cover in the middle of the screen on top of the background which based off of the cover itself.
Is there a way to make the background darker? Like can I make an .xml to modify the background?
also can I maximize to fit the height of the entire windows
For example normally it is like this:

There is still some space above and below the artwork and I want to have no spaces there.\

Thanks in advanced