colors is compared as an int but set as a string

I am running tmuxp 1.7.2 on Arch Linux. When I attempt to load a workspace, I see the following output:

% tmuxp load desktop
[Loading] /home/sam/dotfiles/shell/.config/tmuxp/desktop.yaml
Traceback (most recent call last):
  File "/usr/bin/tmuxp", line 33, in <module>
    sys.exit(load_entry_point('tmuxp==1.7.2', 'console_scripts', 'tmuxp')())
  File "/usr/lib/python3.9/site-packages/click/core.py", line 1134, in __call__
    return self.main(*args, **kwargs)
  File "/usr/lib/python3.9/site-packages/click/core.py", line 1059, in main
    rv = self.invoke(ctx)
  File "/usr/lib/python3.9/site-packages/click/core.py", line 1665, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/lib/python3.9/site-packages/click/core.py", line 1401, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/lib/python3.9/site-packages/click/core.py", line 767, in invoke
    return __callback(*args, **kwargs)
  File "/usr/lib/python3.9/site-packages/click/decorators.py", line 26, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/usr/lib/python3.9/site-packages/tmuxp/cli.py", line 1096, in command_load
    load_workspace(config[-1], **tmux_options)
  File "/usr/lib/python3.9/site-packages/tmuxp/cli.py", line 684, in load_workspace
    if builder.session_exists(session_name) and not append:
  File "/usr/lib/python3.9/site-packages/tmuxp/workspacebuilder.py", line 107, in session_exists
    exists = self.server.has_session(session_name)
  File "/usr/lib/python3.9/site-packages/libtmux/server.py", line 372, in has_session
    proc = self.cmd('has-session', '-t%s' % target_session)
  File "/usr/lib/python3.9/site-packages/libtmux/server.py", line 127, in cmd
    raise ValueError('Server.colors must equal 88 or 256')
ValueError: Server.colors must equal 88 or 256

Inspecting the variables using pdb (python -m pdb /usr/bin/tmuxp load desktop) reveals that self.colors is set to the string '256' (or '88' if the -8 flag is passed) but libtmux is comparing the value against an integer literal (256 or 88).

Start in tmuxp/cli.py at command_load and load_workspace, then trace how tmux_options reaches libtmux/server.py's cmd method. Confirm where the colors value becomes a string and add a regression test covering both default and -8 color settings; done means loading a workspace no longer raises the integer-comparison error.