Dark mode doesn't work on the time series graph

[BinaryFiddler]

Problem Description

If I switch Osprey UI to dark mode, the time series graph's background is still using a light background.

To Reproduce

Steps to reproduce the behavior:

1. Open Osprey web UI with your OS in a dark style

Expected behavior

The time series graph background follows the dark style like the rest of the UI when in dark mode

Additional context

This issue only manifest itself when where is data to plot in the time series graph. Empty graph does not trigger this bug.