import tkinter as tk 

class interfaceGUI:

        def __init__(self):
                # self.bd = BancoDeDados()
                self.proximo_id = 1
                self.root = tk.Tk()
                self.root.title("Minha Janela")
                self.root.geometry("300x200") 
                
                
                self.root.configure(bg="#1e1e1e")  # fundo escuro
                label = tk.Label(self.root, text="Texto", bg="#1e1e1e", fg="white")
                botao = tk.Button(self.root, text="OK", bg="#333333", fg="white")
        
        def executar(self):
                self.janela_principal();

        def janela_principal(self):
                self.root.mainloop()

app = interfaceGUI()
app.executar()