Question

How do I change the color of specific words in a JTextPane just while the user is typing?
Should I override JTextPane paintComponent method?

Answer 1

Overwriting paintComponent will not help you.

This is not an easy one, but not impossible either. Something like this will help you:

DefaultStyledDocument document = new DefaultStyledDocument();
JTextPane textpane = new JTextPane(document);
StyleContext context = new StyleContext();
// build a style
Style style = context.addStyle("test", null);
// set some style properties
StyleConstants.setForeground(style, Color.BLUE);
// add some data to the document
document.insertString(0, "", style);

You may need to tweak this, but at least it shows you where to start.