Color Scheme for Engage

I have created my own color scheme for my Engage interactions.  I've changed the Slide Background to WHITE.  However, there still seems to be a gray shaded area at the top and bottom of the Slide Background that I can't get rid of.  So then when I place a photo graphic on the right side of my Timeline interaction, the white background of the photo is overlapping the gray shaded area.  Can I either get rid of this gray shaded area somehow or have more control over where my graphic is positioned (doesn't seem like there is).  I would really like to have the photo centered vertically on the right side of my Timeline interaction rather than towards the top right.  Any suggestions are appreciated.