<!-- Please search existing issues to avoid creating duplicates. If the matter is security related, please send an email to support@goalert.me instead. --> **Describe the Bug:** Unable to view the date in the tooltip for the alert metrics bar chart when in dark mode **Observed Behavior:** <img width="226" alt="Screen Shot 2022-04-19 at 11 18 57 AM" src="https://user-images.githubusercontent.com/17692467/164049633-9f4743be-325f-440c-aaab-05db0989f5b3.png">