Long or Lung is the term for dragon in Chinese, and the Tian-Long(t’ien-Lung) was the celestial, or “heavenly” dragon. Often yellow or gold, this is the principal dragon type that guards heavenly palaces and pulls divine chariots. It is the symbol of the Emperor of China, and as a result has five toes /claws on each foot.
The Hongwu Emperor of the Ming dynasty copied the Yuan dynasty ruling and decreed that the dragon would be his emblem and that it would have five toes/claws. The four-clawed dragon was typically for imperial nobility and certain high-ranking officials. It was a capital offense for anyone,other than the emperor himself, to ever use the completely gold-colored, five-clawed Long dragon motif. Improper use of claw number and/or colors was considered treason, punishable by execution of the offender’s entire clan.
A side note: Gold coloured dragons have special attributes such as wealth, wisdom, kindness, and the ability to face challenges head on.