How to change font color of Message body

Hi All,
        
I use the below code to send mail message to particular email. how i can change the font and its color of string message .

public void SendMailMessage(string from, string to, string bcc, string cc, string subject, string body)
{
SmtpClient emailClient = new SmtpClient("");
System.Net.Mail.MailMessage message = new System.Net.Mail.MailMessage(from, to, "Mail", body);
message.IsBodyHtml = true;
System.Net.NetworkCredential SMTPUserInfo = new System.Net.NetworkCredential("", "");
emailClient.UseDefaultCredentials = false;
emailClient.Credentials = SMTPUserInfo;
emailClient.Port = 25;
emailClient.Host = "";
emailClient.Send(message);
}

Thanks in Advance