dotfiles/.config/fontconfig/fonts.conf

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
  <!-- Set default fonts -->
  <alias>
    <family>monospace</family>
    <prefer>
      <family>Source Code Pro</family>
      <family>Noto Color Emoji</family>
    </prefer>
  </alias>
  <alias>
    <family>serif</family>
    <prefer>
      <family>Source Serif Pro</family>
      <family>Noto Color Emoji</family>
    </prefer>
  </alias>
  <alias>
    <family>sans-serif</family>
    <prefer>
      <family>Source Sans Pro</family>
      <family>Noto Color Emoji</family>
    </prefer>
  </alias>

  <!-- Add generic emoji family. -->
  <match target="pattern">
      <test qual="any" name="family"><string>emoji</string></test>
      <edit name="family" mode="assign" binding="same"><string>Noto Color Emoji</string></edit>
  </match>

  <!--
  If other fonts contain emoji glyphs, they could interfere and make some emojis rendered in wrong font (often in black-and-white).
  For example, DejaVu Sans contains black-and-white emojis, which we can remove using the following trick:
  -->
  <match target="scan">
      <test name="family" compare="contains">
          <string>DejaVu</string>
      </test>
      <edit name="charset" mode="assign" binding="same">
          <minus>
              <name>charset</name>
              <charset>
                  <range>
                      <int>0x1f600</int>
                      <int>0x1f640</int>
                  </range>
              </charset>
          </minus>
      </edit>
  </match>
</fontconfig>