Changelog callouts display wrong color in emails - shows red instead of brand green

Changelog callouts appear green in editor but render as red/pink when sent via email, despite brand color being set to green.

Reproduction:

1. Set brand color to green

2. Create changelog with green callouts

3. Send test email to inbox (i.e. Gmail)

4. Callouts appear red instead of green

This breaks brand consistency for customers using callouts in changelog emails.