The word for red in Greek used here is pyrros, meaning fire-red. China is symbolised by a red dragon, with the red meaning plain red, so it is not an image of China and has no inner meaning relating to China. This is the only place in the Bible where the name Red Dragon appears.
At the same time the woman appears in the heavens, there rises a Red Dragon with seven heads and ten horns, and a third of the stars fall before it. The constellation Darco, the Red Dragon, also appears in the night skies at the highest level it gets to, about a third high in the night skies. A reference to Satan bringing a third of the angels down with him. The picture of the heads and horns is a little different to the heads and horns on the beast. When dealing with Satan, only seven of the ten horns are associated with kingdoms. Three are not, but this is when referring to the relationship. With the beast, they are all regarded as royals, for all the horns have crowns. This will become clearer when dealing with the heads and horns of the beast in Chapter 13.

This is the only place where we get some idea as to how many angels fell with Satan. To be honest, it is quite vague. I cannot see how you would get millions of angels roaming the earth without it being obvious. Satan was a cherub, as were the coloured horsemen. He was a leader of cherubs, and most likely, the angels that fell with Satan were these cherub angels. We have no idea how many there were, but it will not be many. A thousand all up, with 330 falling. These angels did not just wake up one morning and say, Today, I am going to rebel. They would have been working wickedness on the earth for a long time before they were dragged down by Satan. The dragon is, nearly always, Satan, but this time with the same head and horns as the beast of Revelation 13. The difference is that only seven of these heads have crowns. These European royal bloodlines are ancient and rule Europe today.