import urllib, string
from Tkinter import *
tk = Tk()

coll = StringVar()
coll.set("black")

a = StringVar()
a.set(...)

def nw(*arg):
    try:
        ...
        a.set(b)

        coll.set("red")
        
    except IOError, exc:
        ...
    except NameError:
        ...
p = coll.get()
Label(c,
    textvariable=den1,
    relief="groove",
    borderwidth=3,
    font=("Courier", 12, "bold"),
    foreground=p,
    justify=LEFT,
    width=30,
    height=3,
    takefocus=False,
    ).grid(row=2, column=1, columnspan=2, sticky=NW+SE)

from Tkinter import *
root=Tk()

def foo():
	label['foreground']='red'



label=Label(root,text='hello world')
label.pack()


but=Button(root,text='Change color',command=foo)
but.pack()

root.mainloop()

from Tkinter import *
from tkColorChooser import askcolor               

def colorss():
    but['bg'] = askcolor()[1]
  
root = Tk()
label=Label(root,text='hello world')
label.pack()

but=Button(root,text='Change color',command=colorss)
but.pack()

root.mainloop()

    label["foreground"] = "red"
TypeError: 'NoneType' object does not support item assignment

import Tkinter

root = Tkinter.Tk()

def color(event):
    label ["fg"] = "red"


label = Tkinter.Label(root)
label ["text"] = "color on"
label.pack()

button = Tkinter.Button(root)
button ["text"] = "COLOR"
button.bind("<Button-1>", color)
button.pack()

root.mainloop()