Hi Jorge,
Regretfully the standard footer has limited options, please navigate to Theme Options > Footer to see those options. Height is not one of the options, unfortunately, because height is usually relative to your contents. You can change your Footer Background Color under Theme Options > Renew.
The space that you’re seeing on top and bottom footer content is the top and bottom padding (see the green area on the following screenshot).
If you want to get rid of that or adjust that padding, please add this to your Theme Options > CSS
.x-colophon.bottom {
padding-top: 0;
padding-bottom: 0;
}
You can find the proper CSS code selector using the Chrome browser Developer Toolbar
For the CSS code itself, I suggest that you get started with this tutorial
Hope it helps,
Cheers!