Need to keep old wp color scheme for my clients website

Hi,
Thanks for this plugin. I would like a feature request from you guys. Will you be able to add a option to keep the old pre 3.8. look and feel or atleast the color scheme for wp admin?

I’m asking this because I have used wordpress as the cms for several of my client’s websites and they like the old backend color scheme and look. I have also issued user manuals for them based on old look. Now if I update their wordpress to new version the backend look will change. What shall I do? this change was unnessary for my clients.