Ventured over to /wg/ to see that they are also getting into the spirit of the season (though most of these threads are still fairly new and lacking somewhat in content):

>>>/wg/8113101
"Occult/Esotetic/Mystical" has a bunch of stuff that looks like woodblock prints and a few other odds and ends. Pic related is from this thread.

>>>/wg/8111563
Autumn/Fall papes (Halloween and cozy/gloomy welcome too). Mostly landscapes with the occasional gloomy or Halloween pape

>>>/wg/8114817
Fall Paintings. Mostly what it says on the tin though some retard posted photos. Not a lot posted on this one yet.

>>>/wg/8038078
"Witchy Wallpapers". Mostly thots and anime girls in witch costumes but there's a few gems (and lewds; friendly reminder that /wg/ is a red board). Thread is nearly 2 years old so there's quite a bit in it (but you might've seen it before).

>>>/wg/8102624
Dark Gothic/Eerie/Unnervingly Creepy. Largely mostly black + dim color (white, blue, orange) with a few things that can fit under OP's theme.

>>>/wg/8013462
Warm Color Nature Wallpapers. Not all of it is autumn scenery but a fair bit of the thread is (and some of it is silhouettes against sunset which are at least the right color). A few thots in various states of dress. A few paintings/drawings made their way in too.