I have a RichTextBox that I write a string to every time I click a Form button. The string ends with a newline so each time I add a string, it appends to the bottom of the RichTextBox. Each string begins with the string "Long" or "Short" and ends with Environment.NewLine. I'd like to color each line red if it beings with "Long" and blue if it begins with "Short". How can I do this? If you need further clarification of the question comment below.