Scrolling Presentation Adjustment

I’d like the scrolling presentation images to be not 100% of screen in width and height, but rather 87.5% in width and height.

I’d need that kind of frame around each image, which I also want to be of a different colour for each presentation slide.

Either image itself or the slide needs to be clickable and linked to a different page. I figure for this I could use a button but it has to be invisible and if I set visibility: hidden, it doesn’t show the link as well.

Are these 3 things possible at all?