Your page Layout can be completely changed including the background colors and theme.
If you look to the right side of your page under your Avatar/icon
you will see the link "theme" Click to make a variety of changes to your personal page.
On your page where ever you see a black bar this is the title bar for the module, most likely you will see an edit box.
You can control a variety of options including how many lines of activity or discussions you will see.
Also try clicking on the black bar and dragging the module around on your page. Some items will move to new locations, some will show a strikethrough circle if it can not be moved.