Taken from the context within the film, seeing black and red together signifies death and rage. From the elevator design, the Native American pattern seen within The Gold Room Bathroom (No.53) and Exterior Hallway (No.66, No.81) and having it appear at the final shot (No.91) creates a message that is hard to ignore.
Red and Black also appear in rugs that feature within The Colorado Lounge, viewable during No.64, as well as The Lobby where Jack stalks and murders Halloran (No.77 and No.78).
Related visual evidence
<Image 162- red and black symbol-pattern in the elevator design>
Image 247- red and black luggage (mirrors Image 2138 both indian blankets)
Image 250 - woman wears red and black plaid and red skirt (similar to red and black luggage in Image 247)
Image 703- Danny wears red and black plaid shirt
Image 1777- red and black triangle border - hallway wrapped around Lobby
Image 1788-red and black triangle border -Lobby
Image 1790-red and black triangle border - Lobby
Image 1813-red and black triangle border Lobby/green hallway
Image 1828-red and black triangle border exit hallway
<Image 1828: red and black pattern on the Native American blanket>
<Image 1828: red and black symbol-pattern in the elevator design>
[red/black "star symbolism" Native American rug (rug 5)
(also shows up Image 1785/ replacing the rug shown in No.40)
Image 635 (same basic shot as Image 588)
Image 650 (from this perspective it's rug #1)
Image 761 this configuration is the same as it was in [Image 650, which is different than it was in Image 480, Image 635 the exterior rugs are removed, so that the rugs start with the black and red star symbol- removing the extra 'orange blocky triangle' rug and the brown triangle/family symbol rug]
Image 765- the brown rug just shown in Image 762 is removed, taking away any symbolim to detract from the red and black rug
In this image · No.3
The red and black of the Native American banding in the floor tile design and the red couch and black door frame of the Gold Room entrance.