Elizabeth I enacted the Proclamation Against Excess in 1597. The law was supposed to curb excessive spending on luxury goods. There was a fear that the lower classes, particularly the merchant classes were dressing above their station. Also, many luxurious garments were made of imported fabrics and the government wanted to make sure the English textile industry did not suffer.
The law allowed certain people to wear specific types of clothes. The most extravagant fabrics such as purple satin and gold embroidered cloth were reserved for royalty. Anyone of a status lower than a knight could not wear velvet outer garments. A knight's eldest son was allowed to wear a velvet doublet but his younger brothers could not.
For more information, Google Elizabeth I's Proclamation Against Excess 1597.