Invalid CSS code in verification Email template

Expected Behavior The veryfication code is invisible. Current Behavior The verification code should be clearly visible. Possible Solution Change the CSS in the default email template {{ confirm_code }} "color: #FFF;背景。#a5b3bd" <- invalid CSS code Steps to Reproduce Post a comment on Feedback. Receve the verification Email Can't see the verification code in the Email (as attachments.) Context (Environment) Language: Chinese (tradionnal) Mail system: Gmail