using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Windows.Forms;

    namespace Font
    {
        public partial class Form1 : Form
        {
            public Form1()
            {
                InitializeComponent();
            }
            private void button1_Click(object sender, EventArgs e)
            {
                 if (radioButton1.Checked)
                 {
                    colorDialog1.ShowDialog();
                    richTextBox1.SelectionColor = colorDialog1.Color;
                }
                else
                {
                    colorDialog2.ShowDialog();
                    richTextBox2.SelectionColor = colorDialog2.Color;
                }
            }
            private void button2_Click(object sender, EventArgs e)
            {
                if (radioButton1.Checked)
                { 
                    fontDialog1.ShowDialog();
                    richTextBox1.SelectionFont = fontDialog1.Font;
                }
                else
                {
                    fontDialog2.ShowDialog();
                    richTextBox2.SelectionFont = fontDialog2.Font;
                }
           }
        }
    }