This tutorial demonstrates how to put Excel into dark mode.
By default, Excel (Office 365 version) has the Colorful theme, which means that a combination of green and light gray colors is applied.
If you want to change the Excel theme to dark mode, follow these steps.
1. In the Ribbon, go to File > Account.
2. In the Account section, choose Dark Gray from the Office Theme drop-down menu.
Note: You can also choose a Black, White, or System setting color theme.
As a result, Excel is now in dark mode, which means that the combination of gray and dark gray colors is used.