The episode is called "Ship of Tears" and deals with forced relocation of telepaths. In the 19th century, the US government instituted a forced relocation of Native American populations, the process known as the "Trail of Tears".
According to the Babylon 5 timeline, verifiable telepaths started appearing in Earth's population in the early 22nd century. Everyone assumed it was the result of natural evolution. In fact, it was because of genetic manipulation by the Vorlons.
Bester's line "Weapons supplies" was later one of the phrases featured in the opening sequence of Season Five.
This takes place on July 24, 2260.
27 minutes in the doctor is reviving one of the telepaths rescued from the Shadow ship.... In the foreground is an assistant clearly choosing between green and purple.... Her choice is never shown.