For history's sake, I'm including how I changed the color scheme of
tint2 with wal. Note that I don't use tint2 anymore since I realized
that what I was trying to do with tint2 can already be achieved much
easier and much more polished with GNOME extensions.
Now we no longer have to worry about kitty having an inconsistent color
scheme when changing the color scheme of the rest of the environment,
which means that we can fully use kitty's window management and change
themes with pywal at the same time.
It turns out that placing similar config files (i.e. bspwm-related) in
the same directory is not the way to go about handling dotfiles since
each config file (or dotfile) *should* manipulate only a single program.
This was not the case back when I used urxvt (which would require the
old method of .Xresources), but now that I understand more about how
*modern* dotfiles work (with $XDG_CONFIG_HOME), separating dotfiles by
program became the obvious choice.
Realistically, you won't need my wal config if you are not using my
bspwm setup, since wal does a good job at otherwise changing most other
color schemes that you may find in, e.g., a GNOME or Plasma setup.
Also, after some testing, it turns out that my previous assumption about
systemd was wrong. Placing a service in default.target.wants directly
will cause the service to instead not be recognized by systemd.