#rrggbbaa hex color notation

- UNOFF

The CSS Color Module Level 4 defines new 4 & 8 character hex notation for color to include the opacity level.

IE

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

Edge

  1. 12 - 18: Not supported
  2. 79: Supported
  3. 80: Supported

Firefox

  1. 2 - 48: Not supported
  2. 49 - 72: Supported
  3. 73: Supported
  4. 74 - 75: Supported

Chrome

  1. 4 - 51: Not supported
  2. 52 - 61: Disabled by default
  3. 62 - 79: Supported
  4. 80: Supported
  5. 81 - 83: Supported

Safari

  1. 3.1 - 9.1: Not supported
  2. 10 - 12.1: Supported
  3. 13: Supported
  4. TP: Supported

Opera

  1. 9 - 38: Not supported
  2. 39 - 51: Disabled by default
  3. 52 - 65: Supported
  4. 66: Supported

iOS Safari

  1. 3.2 - 9.3: Not supported
  2. 10 - 13.1: Supported
  3. 13.2: Supported
  4. 13.3: Supported

Opera Mini

  1. all: Not supported

Android Browser

  1. 2.1 - 4.4.4: Not supported
  2. 80: Supported

Blackberry Browser

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

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 46: Not supported

Chrome for Android

  1. 80: Supported

Firefox for Android

  1. 68: Supported

IE Mobile

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

UC Browser for Android

  1. 12.12: Not supported

Samsung Internet

  1. 4: Not supported
  2. 5 - 7.4: Disabled by default
  3. 8.2 - 9.2: Supported
  4. 10.1: Supported

QQ Browser

  1. 1.2: Disabled by default

Baidu Browser

  1. 7.12: Disabled by default

KaiOS Browser

  1. 2.5: Not supported

Only supported in Android WebViews in apps that target Android Pie, due to this issue

Resources:
JS Bin testcase
Edge support request for rrggbbaa