I'll chime in to provide information about pros and cons of each white, black background.
Black
Pros
1. Gives more contrast and visual depth
2. Easier to browser for a longer time, as it doesn’t strain eyes. especially at night.
Cons
1. Mobile users readability of dark background in daylight or bright environment perform worth than white background
2. Forcing users to fixate on the white text for a long time can strain the user’s eyes.
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White
Pros
1. white color is a default color of the website. which means most of the users are more familiar with it.
2. simple
Cons
1. harder to browse for a longer time.
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Other things to keep in mind
1. Perception of color
generally speaking, white color perceived as a safety, purity, and cleanliness and black color as a power, elegance, formality, death, evil, and mystery.
2. User testing
We should remember that we are not only designing for people similar to us but for a broad range of users. What works for one user, might not work for another, a younger audience has different needs and preferences than an older audience. Hence the importance of making sure we know who’s our audience and what are their needs.
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TLDR;
1. Contrast ratio of text, background is more important than actual background-color (7:1 contrast ratio is suggested by W3)
2. Dark background works great as well as white background
if it's done properly.
3. User testing is a must. (when they use? how long? what is the brightness of the surrounding environment, user age, does this color appropriate to the brand?)
References
https://uxplanet.org/dark-side-of-ui-benefits-of-dark-background-12f560bf7165
https://www.droptica.com/blog/benefits-dark-background-your-website/
http://www.color-wheel-pro.com/color-meaning.html
https://www.w3.org/WAI/WCAG21/Techniques/general/G17.html
https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side
https://uxmovement.com/content/when-to-use-white-text-on-a-dark-background/
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My opinion
Ouddict is an information-heavy, text-oriented website. and as far as I know, Ouddict brand represents safety and neutrality.
I'm not sure about the most used device and using time but it seems most of the users browsing the website with their mobile during night time.
considering those things, I suggest use a white background as a default and use the dark background as an option.