Change color of heading and selected row in treeview

Question

So my question is pretty simple, how do I change the color of a header in a treeview in Python?

I looked online and found this option:

ttk.Style().configure("Treeview.Heading", background="black")

But it doesnt seem to work in my code (the header just stays with the default colors)

Other question, how do I change the color of the selected row in my tree?

Here's my code:

class CTABLE:
        def __init__(self, master):

            self.charactersTable = ttk.Treeview(master, selectmode="browse")
            self.charactersTable["show"] = "headings"
            self.charactersTable["columns"]=("Name", "Surname", "Hunger",
                "Fear", "Comfort", "Hapiness")
            self.charactersTable.column("Name", width=100, anchor=E)
            self.charactersTable.heading("Name", text="Name")
            self.charactersTable.column("Surname", width=100, anchor=E)
            self.charactersTable.heading("Surname", text="Surname")
            self.charactersTable.column("Hunger", width=100, anchor=E)
            self.charactersTable.heading("Hunger", text="Hunger")
            self.charactersTable.column("Fear", width=100, anchor=E)
            self.charactersTable.heading("Fear", text="Fear")
            self.charactersTable.column("Comfort", width=100, anchor=E)
            self.charactersTable.heading("Comfort", text="Comfort")
            self.charactersTable.column("Hapiness", width=100, anchor=E)
            self.charactersTable.heading("Hapiness", text="Hapiness")

            for character in characters:
                self.charactersTable.insert("", "end", values=(character.surname, character.name, 
                character.hunger, character.fear, character.comfort,
                character.happiness))
            self.charactersTable.bind("<Double-1>", self.CTClick)
            self.charactersTable.grid(row=3, rowspan=3, column=1, columnspan = 4)

    ctable = CTABLE(CharactersPage)

    ttk.Style().configure("Treeview", background="#636363",foreground="white")
    ttk.Style().configure("Treeview.Heading", background="black")


    root.mainloop()