using System.Drawing;

using System.Drawing.Drawing2D;



class Program

{

    static void Main(string[] args) {

        using (var image = Image.FromFile("blue.png")) {

            using (var g = Graphics.FromImage(image))

            using (var font = new Font("MS Gothic", 24))

            using (var brush = new SolidBrush(Color.White))

            using (var format = new StringFormat()) {

                format.Alignment = StringAlignment.Center;

                format.LineAlignment = StringAlignment.Center;

                g.SmoothingMode = SmoothingMode.HighQuality;

                g.CompositingQuality = CompositingQuality.HighQuality;

                g.DrawString("青", font, brush, image.Width / 2, image.Height / 2, format);

            }

            image.Save("blue2.png");

        }

    }

}

using (var image = Image.FromFile("blue2.png")) {

    using (var g = Graphics.FromImage(image)) {

        g.Clear(Color.Blue);

    }

    image.Save("blue3.png");

}