Changing background (changing the "wallpaper"
of a slide)
From the menu bar, select Format > Background
Select one of the background colors from the pull-down menu, or choose
from a more extensive palette by selecting the More Colors
menu item
You can preview your selections before committing to them by clicking
on Preview
If you are satisfied with the results, you can proceed to committing
to the changes:
click Apply button to change the current slide.
click Apply to all to make the changes to all
of your slides.
If you are using a template and for some reason you need to get rid
of the graphics that the template includes (for example, if you want
to insert a graph and the template graphics are in your way), you can
check the box 'omit background graphics from master'.
Again, you can apply this change to the current slide or to all of your
slides.