Set `pdf-view-midnight-colors` are overwritten by `bg`, `fg` in themes

[iago-pssjd]

I had in my configuration file

(pdf-tools-install)
(require 'pdf-tools)
(add-hook 'pdf-view-mode-hook 'pdf-view-midnight-minor-mode)
(setq pdf-view-midnight-colors '("#FFFF00" . "#000000"))
(require 'doom-themes)
(load-theme 'doom-acario-dark t)

Loading the doom theme after setting pdf-view-midnight-colors overwrites it, as I could check through C-h v pdf-view-midnight-colors, where the current value was that set to fg and bg as defined in https://github.com/doomemacs/themes/blob/master/themes/doom-acario-dark-theme.el

Is such behaviour documented? In that case, where? Could this be avoided?

Thanks!