In antiquity, efforts to control personal regulation were related to the general mode of living rather than of dress. The Greeks had some laws relating to clothing, such as; women could only wear three garments at a time. This may account for why most women went barefoot. The amount of money to be spent of clothing was also regulated by the wealth of the family. Sumptuary laws in Rome included the Lex Orchia which was passed in 187 BC. This related to the number of invited people who might attend a feast. The Lex Fannia was passed in 161 BC and regulated, the cost of entertainment. According to Brundage (1987) the Roman Lex Oppia, was adopted in 215 BC and later repealed 195 BC with the Lex Valria Fundiana. He described the action of Marcus Porcius Cato who argued lifting restrictions of women's dress would invite moral decadence and social upheaval. He was right and both followed in quick pursuit.
Colour and material were very important as a means of depicting rank in Roman time.. Laws were passed restricting peasants (plebs) to one colour; officers could wear two colours; commanders three; and members of the royal household up to seven colours. The colour purple was always reserved for the royal family. Scarlet could be worn only by royal family members and high noblemen.
During the reign of Claudius I (AD 41-54), his marines were ordered to go barefoot after some demanded compensation from the emperor for the marching shoes the marines had wore out. As a result the entire fleet were forbidden from wearing shoes.
At the time of Emperor Aurelian, (Lucius Claudius Domitius Aurelianus (AD 270 - 275) the colours yellow, white, red or green were reserved exclusively for women. The only exception to this was he reserved the right to wear red or purple for himself and his sons. He banned his wife from buying purpura-dyed silk garments because it cost its weight in gold. Only ambassadors to foreign lands might wear gold rings, and men were strictly forbidden from wearing silk garments of any sort.
When Roman soldiers returned victorious to Rome they frequently celebrated by substituting the bronze nails in their caligae (war sandals) with gold and silver tacks. The fashion caught on and patricians began to wear ornamentation on their shoes with gold and jewels.
Such alarm was raised with the fashion for shoe bling Emperor Heliogabalus (AD 218-222) banned the practice. Heliogabalus had his own shoes decorated with diamonds and other precious stones, engraved by the finest artists. During the more luxurious days of the Roman Empire, thongs were decorated with gold and precious stones.
Sumptuary laws and price controls were later imposed by Gaius Valerius Diocletianus (AD 245-313), in AD 301.
During Roman times footwear came in many styles and colours each reflecting class distinctions. Only male citizens were entitled to wear the toga and the calceus (a shoe or short boot). The colour of the calceus always indicated social standing. The reason for this had much to do with the cost of dying materials which was very expensive. Red was, at first, the colour for high magistrates (in the service of Edile); but later became the Emperor's prerogative.
Brundage JA 1987 Sumptuary laws and prostitution in late Medieval Italy Journal of Medieval History 13:4 343-355.