After patching to 7.5.0 UP9, dark mode is configured by default. Upgrading to UP10 where the option is given to change back to light mode does not result in a fix. You can change to light mode, but then everything is just white instead of restoring to the previous UP8 color themes and Juniper style we expected.

Unable to switch back to normal colors and Juniper theme

The ability to switch back to light mode is restored in UP10, however, the fix for the colors and Juniper theme is not resolved until UP12. Please upgrade to 7.5.0 UP12 to get a fix for this.