Darkness theme not applied to scrollbar on YouTube

[aushra]

Bug Information
(visit the affected website → click the moon icon → "Send Feedback" → "Bug Report" → paste here)

• Site: youtube
• Theme: youtubedark
• URL: https://www.youtube.com/?&ab_channel=AntonPetrov
• Darkness Version: 2.0.27 Pro
• Browser: Chrome 98.0.4758.109
• Operating System: Mac OS X 10_15_7
• Resolution: 1792x1120
• Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.109 Safari/537.36

Bug Description
In Youtube: Darkness theme is not applied to the scrollbar on the side of the page. Whichever of the dark themes is picked, the scrollbar remains white.

Screenshots