This is it, folks. This is the story from In A Dark Dark Room that screwed me up. It isn't about ghosts or monsters but it's scary and weird.
I love the colors, too. Jenny and Alfred are this sickly pale color throughout their lives and everything has this subdued funeral home color scheme to it. And the cat, who appears in every story in the book, is at its curious best here in the final panel.
I didn't know there was an audio book of In A Dark Dark Room until I found this video on YouTube. Hopefully I can track it down sometime.