When ForeColor = Color.Red gets displayed as SystemColors.WindowText...

TextBoxForeColorRed.cs

using System;
using System.Drawing;
using System.Windows.Forms;

namespace ChartWindowsFormsApplication
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            textBox1.ReadOnly = false;
            textBox2.ReadOnly = true;
            SetTextBoxForeColorAndText(textBox1);
            SetTextBoxForeColorAndText(textBox2);
        }

        private void SetTextBoxForeColorAndText(TextBox textBox)
        {
            textBox.ForeColor = Color.Red;
            textBox.Text = String.Format("ForeColor={0}, BackColor={1}", textBox.ForeColor, textBox.BackColor);
        }
    }
}