Yes, Todoist has dark themes for all your devices!
Learn how turn it on by changing your color themes.
Q: Does Todoist offer a true black theme for (AM)OLED screens?
A: No. Even though a true black theme would save some battery over our current dark theme, we don’t regard the difference in power consumption significant enough (0.3% mW). Additionally, without an entire redesign, supporting a true black theme would make it harder to distinguish visual hierarchies and depth.
Q: Will Todoist automatically switch to Dark Theme when I switch to Dark Mode on iOS?
A: Yes, there is an Auto Dark Mode setting which will cause Todoist to switch to Dark Theme whenever you set your iOS device to Dark Mode. Learn how to activate it in the iOS instructions here.