_tkinter.TclError: unknown color name "BACKGROUND"

#!/usr/bin/python
 
from Tkinter import *
import ttk
 
class TestListView(Frame):
 
    def __init__(self):
        Frame.__init__(self)
        self.pack()
        self.listbox()
        self.buttons()
 
    def listbox(self):
        global new_customer_lb
 
        scrollbar = Scrollbar(self, orient="vertical")
        new_customer_lb = ttk.Treeview(self, columns=('ID','First Name','Last Name'))
        new_customer_lb['show']='headings'
        new_customer_lb.heading('#1', text= 'ID')
        new_customer_lb.column('#1', width=50, stretch=NO)
        new_customer_lb.heading('#2', text= 'First Name')
        new_customer_lb.column('#2', width=100, stretch=NO)
        new_customer_lb.heading('#3', text= 'Last Name')
        new_customer_lb.column('#3', width=100, stretch=NO)
        new_customer_lb.configure(yscroll = scrollbar.set, selectmode="browse")
        scrollbar.config(command=new_customer_lb.yview)
        new_customer_lb.pack()
 
 
    def buttons(self):
        load = Button(self, text='show customers', command=lambda:self.load_working_customers())
        test = Button(self, text='test new colors', command=lambda:self.test_colors())
        load.pack()
        test.pack()
 
    def load_working_customers(self):
        new_customer_lb.delete(*new_customer_lb.get_children())
        for a in range(0,10):            
            new_customer_lb.insert('','end', values=(a,'first','last'))
 
    def test_colors(self):
        new_customer_lb.delete(*new_customer_lb.get_children())                 
 
        new_customer_lb.tag_configure("evenrow",background='white',foreground='black')
        new_customer_lb.tag_configure("oddrow",background='black',foreground='white')
        for a in range(0,10):            
            if a % 2 == 0:
                new_customer_lb.insert('','end', values=(a,'first','last'), tags=('evenrow',))
            if a % 2 != 0:
                new_customer_lb.insert('','end', values=(a,'first','last'), tags=('oddrow',))
 
root = Tk()
app = TestListView()
app.mainloop()

new_customer_lb.tag_configure("evenrow",bg='white',foreground='black')
new_customer_lb.tag_configure("oddrow",bg='black',foreground='white')