Regression - Issue reporter: red color is not applied in warning text and input border

Environment

• OS version: Ubuntu 18.04
• Browser version: Firefox 83, Chromium 87
• Extension version: release 2020-1
• Last working version: ABP 3.10

Steps to reproduce

1. Open "adblockplus.org"
2. Select "report issue" from the abp popup.
3. Once reached "Details" step, write an invalid email (e.g. "test") and click "Anonymous submission" checkbox

Observed behavior

• email input color border doesn't change to red
• "anonymous submission" warning message is not red

Expected behavior

• email input color border should change to red
• "anonymous submission" warning message should be red

Further information

Regression introduced in https://gitlab.com/eyeo/adblockplus/abpui/adblockplusui/-/issues/819