History window is white instead of purple

Hello,

**Description of the issue: When using private mode only, the history window has the wrong color

How can this issue be reproduced?

  1. Open Brave and go Settings-> Brave Shields and Privacy -> Toggle Private Browsing Only
  2. Open a random website
  3. Click on the … menu and select History

**Expected result: The History window should be purple like the Downloads window and the rest of the interface

Actual results: The History window is white

**Brave Version( check About Brave): 1.22.1

iPhone 11 Pro, iOS 14.3, Dark Mode turned on

Thx a lot