How can I change the theme of my gmail.com page to normal design?

[online...@gmail.com]

Hi all,

I appreciate the gmail team for developing the themes function. But I
love plain outlook.
Now, I found that even my gmail.com page (before I login to my gmail
account), the main page has a mountain view as the background, but
it's very annoying, and distracting. I love the old plain outlook with
a clean white background.

Should anyone know how can I change that back to a clean white
background?
I know I can choose theme/ background after I login into my account,
but what about the page before I login ?

[Ryan Morehart]

I'm sure it will go away eventually. You have no control over the
pages before signing in, they are entirely up to Google. For now
they're just promoting the new themes.

Ryan