Blog Question

Does anybody know how to make a "transition" from one photo to another with a "fade in" or "wipe" or something like that? For example... taking a black and white photo or sepia photo like the one shown and having it dissolve into a color photo like the other picture. I'm looking for the html code to insert into the blog header. I have looked on Apple and around the internet but just can't figure it out. This is something that I would like to create in order to show one of our favorite blogging friends. Thank you so much!