from tkinter import *

color = 'red'
clicks = 0

root = Tk()
root.geometry('500x500')
root.configure(bg='red')
root.title(f'Clicks: {clicks}')


def click():
    global color
    global clicks

    clicks += 1
    root.title(f'Clicks: {clicks}')

    if color == 'red':
        button['text'] = 'Change color to red'
        color = 'blue'
        root.configure(bg=color)

    elif color == 'blue':
        button['text'] = 'Change color to blue'
        color = 'red'
        root.configure(bg=color)


button = Button(root, text='Change color to blue', command=click)
button.pack()

root.mainloop()