[OS X Emacs] Aquamacs (dev version) and custom themes

[Win Treese]

In the development version of 3.4 (downloaded 8/22/2017), I've been having trouble with color-theme-solarized. The problem is that new frames (typically a pop-up Help frame) don't use the theme settings. Also, the message "Failed to load theme: solarized" appears in the `*Messages*` buffer.

A note on Emacs Stack Exchange (https://emacs.stackexchange.com/questions/28849/theme-not-loading-on-startup) suggests that `package-initialize` must be called before the theme is set, which makes sense.

In Aquamacs the theme is set in `~/Library/Preferences/Aquamacs Emacs/customizations.el`, and it's not clear to me the proper way to slip in `package-initialize` before `customizations.el` is loaded.

I tried adding `package-initialize` as the first thing in `customizations.el`, which seems to work, but I'm not sure that's the right answer.

Any suggestions on the right way to do this with Aquamacs? 

Thanks,
Win