How can I make Robot type a `:`?

I want to type : using Java Robot. However, I'm getting an IllegalArgumentException. My code is:

robot.keyPress(KeyEvent.VK_SHIFT);
robot.keyPress(KeyEvent.VK_COLON);
robot.keyRelease(KeyEvent.VK_COLON);
robot.keyRelease(KeyEvent.VK_SHIFT);

The exception is:

java.lang.IllegalArgumentException: Invalid key code.].

I also tried with:

robot.keyPress(KeyEvent.VK_SHIFT);
robot.keyPress(KeyEvent.VK_SEMICOLON);
robot.keyRelease(KeyEvent.VK_SEMICOLON);
robot.keyRelease(KeyEvent.VK_SHIFT);

How can I solve this problem?