Comment # 11 on bug 1110412 from Yunhe Guo

Correct previous comment:

openSUSE provided a configuration with higher priority (60-family-prefer.conf)
than fontconfig (61-latin.conf). In openSUSE's 60-family-prefer.conf DejaVu
Sans has been removed from sans-serif list.

And I tested if only install Noto Color Emoji and DejaVu fonts, Chromium and
Firefox can render almost all Emoji correctly (except several common symbols).
Tested web pages:

https://en.wikipedia.org/wiki/Emoji
https://getemoji.com/

However, KDE/Qt applications, like Konversation, KAddressbook, still use some
DejaVu monochrome symbols.