This Grateful Dead lyrics page has an interesting bit about this:

a posting I found from Catherine Yronwode helpfully explains a bit more about the reference to "dressed in red":
"White folks, accustomed to black being the colour worn both for funerals and for post-funereal mourning, sometimes think that references in blues songs to dressing in red signify a party atmosphere or happiness over a person's death. Not so. In Africa, and among African-Americans in earlier times, drssing in red has been a funerary custom. As such, it is reminiscent of burial with red ochre pigment, which was used among neolithic people (the "red paint people") the world around. The religious idea behind this custom is that as a baby is born from the mother's womb through blood, so will rebirth occur (after interrment in Mother Earth) through blood."

And it also passes on a comment relating to the question I raised: According to "Masters Of The Instrumental Blues Guitar", Louis Collins is a murder ballad which Mississippi John Hurt composed from hearing people talk about a shooting.