During the 18th century, in the years before the revolution, most wealthy people imported their textiles and luxury goods despite strict laws against importing many types of textiles. The French textile industry languished and so did all the associated businesses like the dyers, the farmers who produced the raw materials, the weavers and the shopkeepers.
During the Middle Ages, the region around Toulouse had produced woad - a natural blue dye that is similar to indigo. By the time Napoleon came to power, imported indigo was the preferred blue dye used in France. As a result, the French producers of woad were suffering and the entire Toulouse region was economically weak.
Napoleon chose the color blue for the French military uniforms in order to revive the production of woad. He decreed that the cloth for the military uniforms be produced in France with French wool, dyed blue with French woad and woven by French textile mills. The region that produced woad thrived again under the Republic.