In 1603 an ethnic Chinese revolt took place right after a visit to Manila by three official Mandarin Chinese representatives who arrived in a large fleet of ships. They said they were searching for "a mountain of gold". This claim prompted the Spanish to conclude that there was an imminent invasion from China in the making. At the time the local Chinese outnumbered the Spaniards by twenty to one, and Spanish authorities feared that they would join the expected invading forces.
The revolt was led by Joan Bautista de Vera, a wealthy Catholic Chinese who was highly esteemed by the Spaniards, and feared and respected by the Sangley. During preparations, he had continued to mingle with the Spanish and posed as their confidant. He carried out a census to ascertain the number of men of his race. When he found that there were enough Chinese men to carry out the revolt, he gave orders to construct a fort and quarters at a hidden location in Tondo, where rice, provisions, and weapons were stored. The Sangley began to gather there, planning the insurrection for St. Andrew's Day, but when they realized that their intentions had been discovered, decided to take action before that day. On the eve of St. Francis, two thousand Sangleys met in the quarters. Joan Bautista de Vera told the governor that the Sangleys were meeting on the opposite side of the river. Suspicious, the governor had Bautists de Vera arrested carefully guarded. He was later executed for his part in the revolt.
The insurrection was put down by joint Spanish, native and Japanese forces led by the interim Governor-General, Luis Pérez Dasmariñas. During the revolt were killed many of the 20,000 Chinese who resided in the colony. In the aftermath, the Chinese Ming government denounced those events, wanting to preserve their commercial interests. In 1605 a Fukien official issued a letter saying that the Chinese who had participated in the revolt were unworthy of China's protection anyway, describing them as "deserters of the tombs of their ancestors".
During the revolt were displayed many flags and banner by chinese ; according to what reported on the book:
The Philippine Islands, 1493-1898 , volume 6 Emma Helen Blair , 1915 -
" Among the enemy's flags were two that contained characters in the
Sangley language, which, translated into our Castilian vernacular,
read as follows:
"The leader and general of the kingdom of Espana ...  so that
all the Chinese take part together in this affair and obey us by
destroying root and branch these hostile robbers, whom we have against
our will, both Castilians and Japanese. We the Sangleys swear that
after the conquest of this city we shall share the lands, even to
the very herbs, with equal shares, as brothers."
(  At this point, in the printed original, follow the words _tribuleco llamadotin_--evidently some typographical error).
As we can see the flags were particular and had some inscriptions on them, following shapes and features of the flags of those times had triangular , square and rectangular shapes; the colors were red, blue, yellow, white, green and black.
Prof. Gregorio Zaide on his book ( " The Philippines since pre-Spanish times.-v. 2. , 1957 )
wrote : "... the Chinese unfurled their dragon flags and attacked Tondo and Quiapo, putting the buildings on fire and committing frightful slaughters. ... ".
We must consider who the dragon flag, symbol of the Qing Dynasty or Manchu Dinasty appeared on its flags after 1644 (until 1912 circa ); in 1603 the ruler of China was the Ming Dynasty and also chinese communities in the Archipelago had great respect and consideration for the Empire of the Great Ming , so it seems to be a contradiction or a mistake, but it is not... The dragon is a traditional symbol of all chinese communities and has its roots in chinese mythology and traditions; dragon traditionally symbolize potent and auspicious powers, particularly control over water, rainfall, hurricane, and floods. The dragon is also a symbol of power, strength, and good luck for people who are worthy of it. With this, the Emperor of China usually used the dragon as a symbol of his imperial power and strength.
The Manchu Dynasty had a golden/yellow dragon as symbol and the Great Ming Empire had a red dragon.