Making Combo Selected Consistent

with the tree and rest of site
Making Grid Select Consistent

variabilizing green and red colors
adding a selected color variable
Merge remote-tracking branch 'origin/pr/668' into develop

* origin/pr/668:
  Making Grid Select Consistent
  Making Combo Selected Consistent

Conflicts:
	_build/templates/default/sass/_colors-and-vars.scss
	_build/templates/default/sass/_tree.scss
	_build/templates/default/sass/_xtheme-modx.scss
	manager/templates/default/css/index.css