Commission Exhibit (CE) 150 is the well-known brown shirt Oswald was arrested in (below left). CE 151 (below right) was a light-brown shirt of Oswald's. CE-151 is not included in a November 27, 1963 Secret Service list of Oswald's clean clothes taken from his N. Beckley rooming house (it doesn't look like a freshly laundered shirt in the photo).
According to Will Fritz's transcription of FBI Agent Bookhout's interrogation notes, Oswald said he "changed shirts" back at his rooming hours and he described the shirt as "reddish." CE 151 was among the non-clean clothes found at Oswald's rooming house.
Sean Murphy believes—and I agree—that the disheveled looking "light brown" long sleeve shirt itemized as CE 151 is the "reddish" shirt that Oswald wore to work the day of the assassination. And we submit that it's the very shirt that we see Prayer Man wearing.