ditch grub testing values for ubuntu

I forgot to undo the demo values in there. these settings generally do not
apply as our theme overrides them. however, in the event that gfxmenu isnt
working for whatever reason, grub would use these values to theme the
standard menu. when that happens the user would then get the absurd testing
colors. let's not risk it and instead use non-offensive default black-white
color schemes.