How to change the cursor blink color?

Answer 1

"Cursor" is used to refer to the mouse cursor which does not blink.

So, I assume you are talking about the caret which is used in a text component:

textField.setCaretColor(...);

Edit:

The above suggestion does it for one text field. To change it for all text fields you should be able to use the following at the start of your program:

UIManager.put("TextField.caretForeground", new ColorUIResource(...));