Can I use
?

prefers-color-scheme media query

- WD

Media query to detect if the user has set their system to use a light or dark color theme.

IE

  1. 5.5 - 10: Not supported
  2. 11: Not supported

Edge

  1. 12 - 18: Not supported
  2. 79 - 85: Supported
  3. 86: Supported

Firefox

  1. 2 - 66: Not supported
  2. 67 - 80: Supported
  3. 81: Supported
  4. 82 - 83: Supported

Chrome

  1. 4 - 75: Not supported
  2. 76 - 85: Supported
  3. 86: Supported
  4. 87 - 89: Supported

Safari

  1. 3.1 - 12: Not supported
  2. 12.1 - 13.1: Supported
  3. 14: Supported
  4. TP: Supported

Opera

  1. 9 - 60: Not supported
  2. 62 - 70: Supported
  3. 71: Supported

iOS Safari

  1. 3.2 - 12.4: Not supported
  2. 13 - 13.7: Supported
  3. 14: Supported

Opera Mini

  1. all: Not supported

Android Browser

  1. 2.1 - 4.4.4: Not supported
  2. 81: Supported

Blackberry Browser

  1. 7: Not supported
  2. 10: Not supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 59: Not supported

Chrome for Android

  1. 85: Supported

Firefox for Android

  1. 79: Supported

IE Mobile

  1. 10: Not supported
  2. 11: Not supported

UC Browser for Android

  1. 12.12: Not supported

Samsung Internet

  1. 4 - 11.2: Not supported
  2. 12.0: Supported

QQ Browser

  1. 10.4: Not supported

Baidu Browser

  1. 7.12: Not supported

KaiOS Browser

  1. 2.5: Not supported

Support will also depend on whether or not the OS has support for a light/dark theme preference.

Resources:
Chromium implementation issue
Firefox implementation bug
MDN article
Web.dev article