Sorry for the late 3-day response. As for how to use Tsuno's bar script, it's simple. You define a bar method in Window_Base like this one.
def draw_hp_bar(actor,x,y,width = 140)
hp = actor.hp
max_hp = actor.maxhp
percentage = ((hp * 1.0) / max_hp)
bar_width = (percentage * width)
empty_width = (width - bar_width)
gray = Color.new(50,50,50,255)
hp1 = Color.new(248,45,30,255)
hp2 = Color.new(248,116,30,255)
hp3 = Color.new(247,154,30,255)
hp4 = Color.new(245,203,30,255)
hp5 = Color.new(247,231,30,255)
hp6 = Color.new(243,247,30,255)
hp7 = Color.new(199,247,30,255)
hp8 = Color.new(138,247,30,255)
hp9 = Color.new(111,247,30,255)
hp10 = Color.new(79,247,30,255)
hp11 = Color.new(51,247,30,255)
#draw empty if any
self.contents.draw_gradient(x + bar_width,y,empty_width - 1,10,[gray])
#draw gradient
self.contents.draw_gradient(x,y,bar_width,10,[hp1,hp2,hp3,hp4,hp5,hp6,hp7,hp8,hp9,hp10,hp11])
#draw border
self.contents.fill_rect(x,y,width,1,Color.new(0,0,0,255))
self.contents.fill_rect(x,y,1,10,Color.new(0,0,0,255))
self.contents.fill_rect(x + width,y,1,10,Color.new(0,0,0,255))
self.contents.fill_rect(x,y + 9,width,1,Color.new(0,0,0,255))
end
I tend to use 10-12 colors per bar. Though, if you wanted to, I suppose you could use an array to store the colors into instead of just using 10 different variables...
; Now all you gotta do is call the bar inside a window. The arguments in this method are actor, x, y, and width. All in all, a simple method to utilize.
As for where to put the script...anywhere should work fine, though I prefer to keep all my scripts in a different order. I.E. Scripts altering the hidden classes go first. Game_ scripts go second. Sprite/Spriteset scripts go third. etc. like the way they're laid out by Enterbrain.