So, Jacquie, to see the shadow go to any forum, click on any thread and travel down the page. As soon as you start reading the posts the menu bar will begin to float down the page with you and the shadow will appear.
I really don't notice it yet, unless someone directs my attention to it. I just got my first treemail since the change and likely would have missed it had it not come with a thread attached.
I remove my glasses to read and the little bit of red around the envelope fades into the rest of the itty-bitty red icons already up there on the left until it's all but unnoticeable. I guess it's time for bi-focals for me, eh?