Making display go black and white with button

Hi,

What I currently have is a menu with a couple of buttons and text with changes depending on what button you select. The size of my canvas is the default 550x400. Throughout all of the timeline I have a button called help which is there to give assistance if the user ever needs it.

What I would like this button to do once clicked is fade the canvas to black and white and fade in a box of say 200x200 in size in a specific colour, which will contain help information (just text). There will then be a button on this area to go back to the general view. Is this possible? And is it also possible to fade out wherever you are on timeline rather than just say the beginning screen.

Thanks