TKinter can't change background color of window (MacOS M1 Max)

Question

For some reason I cannot change the background color of my window. it just appears black every time. I have tried:

• top.config(bg='blue')
• top.config(background='blue')
• top.configure(bg='blue')
• top.configure(background='blue')
• top['bg']='blue'
• top['background']='blue'

Code: (Everything else works perfectly its just the background color)

def openWorkoutCustomization():
    top = Tk(className='Customize your Workout!')
    top.config(background="blue")
    top.title("Customize Your Workout!")
    top.geometry("900x600")

    variable = StringVar(top)
    variable.set(workout_list[0])

    w = OptionMenu(top, variable, *workout_list)
    w.pack()

    button = Button(top, text="Start", command= lambda: startWorkout(variable.get()))
    button.pack()

    top.mainloop()