Dark Theme Viewing Option for Zazzle WEBSITE

[BevStuff]

I request that you, Zazzle, to please develop a scale of Dark Theme Options for people to be able to choose a dimmer background then WHITE. I don't mean black, but a scale of choices ranging from white to medium gray would be my suggestion. 
I use dark theme on X/Twitter, You Tube, my email, my phone messages, my photo shop---everywhere I can possibly use that option. As a designer, I spend way more time looking at Zazzle then a customer, so I'd really appreciate an pption to choose a grayer background view.

(yes, I did use light settings to tone the brightness of the white down a bit, but cannot make it as dark as a dark theme offers with the light setting.)