The new Power BI filter pane goes live in all reports
Published date: January 03, 2020
The new filter pane allows you to format the filters pane to match the look and feel of your report. You can format the filters pane differently for each page in the report.
You can now modify the default settings of the filter pane with a theme file. Read Use Report Themes in Power BI Desktop article to learn more.
If you wish to retain the old dark theme, use this theme Json that changes the filter pane formatting to dark theme.
Read the following articles to learn more: