This image comes from a Bronze Age royal tomb at Qatna in modern-day Syria, which remained sealed until the palace was destroyed around 1340 BCE. The textile fragments found there were exceptionally fine and are described by the researchers as prestige objects used by the highest levels of society.
The blue pattern shown here is a reconstruction of one of the surviving textile fragments. Chemical analysis of that fragment found the same shellfish-dye compounds identified elsewhere in the tomb, and the overall chemical profile points specifically toward Hexaplex trunculus as the likely source.
For the Techeiles discussion, the importance of this find is straightforward: a highly prestigious Bronze Age textile associated with royalty could contain a distinctly blue pattern produced from the same general shellfish-dye tradition associated with Techeiles. The paper itself labels the textile pattern as blue, even though the broader class of dye is discussed under the heading “Royal Purple.”
Bottom line: Blue was not merely a cheap or secondary color standing in contrast to prestigious shellfish purple. In the ancient Near East, blue shellfish-dyed textiles could themselves appear in an elite royal context. This is important evidence against treating a distinctly blue Techeiles as somehow culturally implausible simply because shellfish dye was also famous for producing purple.
