Zebra Notes: Open, Save, Save As, and Format with a Rich Text Box
Continue with the Notes Application.
Next we will write the code to change the color of the selected text.
Add a button to the toolbar and name it toolStripColor. Download this image to use for the button: 
If you wish, you can add a menu item for the color also.

Write the code shown below:
private void toolStripColor_Click(object sender, EventArgs e)
{
SelectColor();
}
private void SelectColor()
{
// Display the color dialog and change color of selected text.
// If no text is selected this has no effect.
Color selectionColor = richTextBox1.SelectionColor;
colorDialog1.ShowDialog();
richTextBox1.SelectionColor = colorDialog1.Color;
}
Click Save All
at this point and run the program.
That's all! Congratulations on completing all of the lessons in csharp!