I will try to answer you question as well as I can...
~ About the colors ~
Indeed, colors do have symbolic meanings when it comes to the subject tarot.
The combination of white and red, particularly in flowers and clothing, is one often seen in the Rider-Waite decks, as well as many other decks . This combination of white and red can be viewed at a couple of different levels. First, white represents the passive principal and purity or innocence, while red represents the active principal and passions or lusts. This can be a bit confusing, because in the black/white pairing above, white represents the masculine, while in the white/red pairing, white is normally associated with the feminine principal. The white/black appears on only a few cards white/red is everywhere you look and is often used in cards where duality is part of the theme . The Magician shows his ability to use both of these opposite energies by wearing red robes over a white robe, and is surrounded by red roses and white lilies.
At a more esoteric level, red and white are key colors in alchemy, and this is one of the reasons for their use in the post-RW versions of the tarot, as well as some earlier versions. In alchemy, red is again associated with the masculine elements and white with the feminine. In the course of the Great Work (transforming lead to gold), the masculine and feminine elements are first separated and purified from baser materials and then "married" together in the final step the red (mercury) with the white (silver) to make gold. Red also represents blood and white represents mother's milk, and in some versions of the Temperance card, you can see the two streams of blood and milk intermingling (Wheel of Change Temperance). There are strong undercurrents of sexuality that run through the alchemical symbols, although this is largely subdued in the Rider-Waite deck.
~ about the numbers ~
Numbers in the tarot are represented and used in many different ways. Iwill focus mainly on the major arcana, because in the minor arcana the use of numbers is fairly obvious. Each number is usually represented by that number of the suit symbols somewhere in the card (there are occasional additions to this, such as the infinity symbol in the Two of Pentacles card). In contrast, numbers are used in the major arcana to symbolize various esoteric concepts, and are usually worked into the drawing more subtly.
. Please note, many of these are religious and metaphysical symbols, and this words describes these symbols without endorsing or ascribing to these specific faiths or beliefs.
As for your question about the number zero (you have asked about this number specifically). Only the Fool is numbered zero, and it is important to realize that in early tarot decks, trumps were not numbered at all. These 22 cards were usually referred to as 21 Trumps plus the Fool, which stood outside the series of trumps, neither at the bottom or the top, or anywhere in between. It had its own special scoring rules in the game of Triumphs as well. In fact there is still disagreement about whether the Fool belongs at the beginning or the end, and perhaps the correct answer is both. As a Zero, the Fool represents a direct incarnation of the Universal nothingness true consciousness does not arise until the 1, or the Magician. The circular aspect of zero can be found in two other cards 10 The Wheel of Fortune, and 21 The World. These three cards represent the beginning, middle, and end of the series of Trumps and the Fool's journey, and as such encompass more of the Whole than the other Trumps. They form a never-ending cycle, circle, or spiral within which the dance of incarnation takes place. The circular nature of these cards suggests that one should not view the trumps as a linear progression, but rather a repeating cycle.
~ About Towers ~
Many towers appear...
. Most notable are the twin towers depicted in Death and the Moon. These are both gateways and these twin towers have the same symbolism as the twin mountains on other cards. In Death, the towers are far in the background, but as you look through them, the sun is rising and it appears to actually be a different world. When you step through these towers, you will never be the same and there is no returning whence you came. Also, a stream flows to the towers and fills the space between them the only path to these towers is to lose your ego in the subconscious and follow the collective stream where it takes you. The Towers of the Moon are somewhat different there are not so far off and there is a path that leads to them, however, the path is very long and winding, and leads into a dark land that is more shadowed than the foreground. There are tiny windows in the tower and you wonder if someone may be watching. These are almost like the eyes of the conscious mind, walled off and we are walking in the subconscious, well below the towers and the thoughts going on above. Lastly, of course, there is the single tower depicted in the Tower card. This tower represents our ego, our material and intellectual constructs, our protective devices, and our arrogance note its similarity to the Tower of Babel. It has a large golden crown on top, which is the first to be blasted away, symbolizing the loss of our pride and the humility that comes with this card.
I have gathered here all of what I knew and searched about tarot, I hope that this is the answer you were looking for.
