RichTextBox exclude textbox input

Question

I color some terms and codes entered in the richtexbox, but if the data comes from the text box, how can i disable the this coloring function for data came from textbox. Here is my code:

private void CheckKeyword(string word, Color color, int startIndex)
    {
        if (this.richTextBox1.Text.Contains(word))
        {
            int index = -1; 
            int selectStart = this.richTextBox1.SelectionStart;

            while ((index = this.richTextBox1.Text.IndexOf(word, (index + 1))) != -1 )
            {
                this.richTextBox1.Select((index + startIndex), word.Length);
                this.richTextBox1.SelectionColor = color;
                this.richTextBox1.Select(selectStart, 0);
                this.richTextBox1.SelectionColor = Color.Black;
            }
        }
    }

    private void richTextBox1_TextChanged(object sender, EventArgs e)
    {                        
        this.CheckKeyword("#example", Color.FromArgb(141,0,78), 0);
    }

so if textbox's text include the "#example" string i dont want to change color.

Also, Second way: if the incoming string is printed in quotes, how can I uncolor it?