Сменить цвет кнопки при нажатии

        private void button1_Click(object sender, EventArgs e)
        {
            Random rand = new Random();
            switch (rand.Next(0,5))
            {
                case 0: button1.BackColor = Color.Lavender; break;
                case 1: button1.BackColor = Color.Cyan; break;
                case 2: button1.BackColor = Color.Magenta; break;
                case 3: button1.BackColor = Color.Yellow; break;
                case 4: button1.BackColor = Color.Black; break;
 
            }
        }

            Random rand = new Random(); int c=rand.Next(1, 5);
            if (button1.BackColor != SystemColors.Control) c = 0;
            switch (c)
            {
                case 0: button1.BackColor = SystemColors.Control; button1.UseVisualStyleBackColor = true; break;
                case 1: button1.BackColor = Color.Cyan; break;
                case 2: button1.BackColor = Color.Magenta; break;
                case 3: button1.BackColor = Color.Yellow; break;
                case 4: button1.BackColor = Color.Black; break;
 
            }

                this.button3.ForeColor = Color.Gold;
                this.button3.BackColor = Color.Red;

private void button1_Click(object sender, EventArgs e)
{
        Random r = new Random();
        this.button1.BackColor = Color.FromArgb(r.Next(0, 256), r.Next(0, 256), r.Next(0, 256));
        // Добавить прозрачность
        this.button1.BackColor = Color.FromArgb(r.Next(0, 256), r.Next(0, 256), r.Next(0, 256), r.Next(0, 256));
}

IF (button3.ForeColor == System.Drawing.Color.Gold)
{
this.button3.ForeColor = Color.Gold;
this.button3.BackColor = Color.Red;
}
else 
{
this.button3.ForeColor = Color.Red;
this.button3.BackColor = Color.Gold;
}