Blue

Blue was one of the three principal colors used in the tabernacle and priestly vestments, consistently listed alongside purple and scarlet in the Mosaic instructions (Ex. 25:4; 26:1, 31, 36; 28:5–6). The Hebrew tekhelet designates a shade ranging from sky-blue to violet, produced from a dye derived from a marine creature—likely the Murex trunculus snail—making it an expensive and prestigious color. The tekhelet cord was incorporated into the fringes (tzitzit) that Israelites were commanded to wear as a reminder of the commandments (Num. 15:38–40).

Blue appears throughout the sacred furnishings: the high priest's robe was entirely of blue (Ex. 28:31), the ark, table, lampstand, and altars were covered with blue cloth when transported through the wilderness (Num. 4:6–12), and blue thread was woven into the curtains and veils of the sanctuary. The association of blue with priestly dignity and divine presence made it a color of particular sacred significance in the Israelite cult, distinguishing holy objects and holy persons from common use.