There is no way you can have something hidden/invisible and clickable.
One way to do this would be to replace the real image with a blank image. This could be the same colour as the background to make it look like the real image has disappeared.
Setting the ForeColor
of the picture box would have no effect for an image.
Another way might be to set the opacity of the image to a very small positive value so that the image isn't completely transparent. This should still be clickable but it might still be visible if the user fiddles with the monitor brightness/contrast.