C# | Bitmapの背景色を塗りつぶす方法

背景色を塗りつぶすサンプル

public Bitmap bmp = new Bitmap(128, 128);

using (var gfx = Graphics.FromImage(bmp))
{
    gfx.FillRectangle(
        new SolidBrush(Color.FromArgb(208, 25, 25, 112)),//navy
        new Rectangle(0, 0, bmp.Width, bmp.Height));

    gfx.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;
    gfx.SmoothingMode = SmoothingMode.HighQuality;
}
bmp.Dispose();