How do I change text cursor color?

How do I change the text cursor color? Not the mouse cursor. I mean the blinking vertical line that appears in every textbox.

Have you been able to change the color?

No I've not been able to change the color of the text cursor yet.

For most controls (edit fileds, dropdowns, etc) the caret doesn't have a "color". It inverts the color of the pixels behind it - white becomes black, blue becomes yellow, etc. Check out the second paragraph here: About Carets (Windows)

Technically it is possible for a control to choose a custom color or shape, but I have not seen any that do it. Most controls simply set the width and height of the blinking rectangle.