This post shows you how to random color in C#.

You can use Random class

Random rnd = new Random();

then use the Next method to random value.

Color color = Color.FromArgb(rnd.Next(256), rnd.Next(256), rnd.Next(256));

Using FormArgb method to create color from random value.

As you know, maximum value is 256 colors. We will random value from 0 to 256