For the GUI addition:
under HeroScript tab open GUIeditor
on the gui editor panel, double click on e_StatusBar to open the gui
on the properties panel, select e_StatusBar for adding a gui as a child
on the gui editor panel, double click on _panel to add it to the gui
on the properties panel, select _panel to change its values
" ", change name to manaPanel hit enter
" ", set position to 6,39 hit enter
" ", set size to 160,7 hit enter
" ", set defaultStatePresentation color to 0,0,0,1 hit enter
on the gui editor panel, double click on _panel to add it to gui as a child
on the properties panel, select _panel to change its values
" ", change the name to manaSlider hit enter
" ", set size to 80,7 hit enter
" ", set defaultStatePresentation color to 0,0,1,1 hit enter
top left side hit the save Icon, then the close Icon.
for diff colors set the rgb of that last field
red = 1,0,0,1
green = 0,1,0,1
blue = 0,0,1,1
yellow = 1,1,0,1
purple = 1,0,1,1
cyan = 0,1,1,1
black = 0,0,0,1
white = 1,1,1,1