Hi,
Google Docs doesn't support dark themes at this time. Please share your concerns about this directly with the Docs team by opening a Docs document and going to Help > Help Docs improve. The team is unable to respond to individual users, but they do review all feedback sent to them and use it to improve the app over time.
Jo S.
PE volunteer
(not a Google employee)
⚠️NOTE: This is a peer-to-peer community. The helpers in the forum are volunteers known as Google Product Experts who are not Google employees. We do not have access to users' accounts or data. We merely provide suggestions and advice based on our product knowledge and experience.⚠️