The colors in antique oriental rugs change with the location of tribes weaving them.
Why? Because weavers relied on natural dyestuffs for the colors they used in their weavings.
And… color is geographical, meaning the natural plants and insects in a weaver’s environment will eventually play a role in the brilliant colors of their rugs. Shades of red will often tell the student of textiles from where an old rug originates.
Red is a widely used color, ranging anywhere from pale pink, red orange to bright magenta.
The most common source of red dye comes from the root of the madder plant where the pigment is the most concentrated. This plant originates from Persia and the Mediterranean region. Madder produces a more orange red or pale salmon color. The roots are left out to dry before being crushed into powder. This powder and a mordant are mixed to create a stable fix dye solution into which goes the newly spun wool. You can think of this process as steeping tea, the longer the yarn is saturated the darker the red will be.
Cochineal insects are another source of red, as they produce a blueish or bright magenta hue. Though they are not a native species in the Middle East, having originated from Mexico, these dyes made their way into Persia around the 16th century by Spanish conquistadors. Since then, cochineal has been used in Meshad, Iran, where weavers steeped their yarn in lime prior to dying it. It was believed this produced a more gleaming red.