I just bought and paid for X4, but I find the graphite theme totally unusable.
I cast my vote STRONGLY for restoring the user option to use the standard background. Working with the graphite theme is very distracting and actually causes discomfort to my eyes. I suspect it's something about the contrast of the menus. In any case, if the option were returned to the user, it could always be set to graphite for "fine tuning" colors where excessive back-light could be distracting.
I guess I'll put my bought-and-paid-for version back on the shelf until it's fixed. X3 is at least usable.
Thanks, in advance, for any quick attention that could be given to making X4 usable....