Many devices now have a system-wide dark mode (dark design). Despite this, the Chrome browser is always displayed in the light design by default. In the settings, the dark design can be selected, but also the design of the system settings.

Android 9 | LG UX 9.0
Step 1:  Open the  Chrome  Browser
Step 2:  Open the  Menu
Step 3:  Open the  Settings
Step 4:  Tap on  Themes
Step 5:  Choose between  System default ,  Light  and  Dark
  1. Open the Chrome Browser
  2. Open the Menu
  3. Open the Settings
  4. Tap on Themes
  5. Choose between System default, Light and Dark

LG Instructions