import tkinter as tk
from tkinter import simpledialog

class NameDialogApp(tk.Tk):
    def __init__(self):
        super().__init__()

        self.title("Name Prompt")
        self.config(bg="blue")

        self.name_label = tk.Label(self, text="Enter your name:", bg="blue", fg="white")
        self.name_label.pack(padx=10, pady=10)

        self.name_entry = tk.Entry(self)
        self.name_entry.pack(padx=10, pady=10)

        self.submit_button = tk.Button(self, text="Submit", command=self.display_name)
        self.submit_button.pack(padx=10, pady=10)

    def display_name(self):
        name = self.name_entry.get()
        self.name_label.config(text=f"Hello, {name}!")

if __name__ == "__main__":
    app = NameDialogApp()
    app.mainloop()