Background image in Vertical menu

I’ve setup a slideshow for the background on home screen. (Settings/Appearance/Widgets/Set slideshow path )
If I set the menu style setting to “normal” (horizontal menu) the pictures in the slideshow display normal. (Settings/Skin settings/Home menu style )
If i set the menu style to “vertical” (my preference) then the slideshow pictures appear washed out or hazy.
Is there a way to correct this?