Dear Master Cecil, I noticed there has been a lot of crystal Wu Lou that comes in various colors,sizes and other combinations. I've seen white, black, green, blue and even clear crystal Wu Lou selling at some of those shops. Are there any significance as to what kind of color and size that one should buy? There's also crystal Wu Lou that comes with other combinations such as those with ancient coins as well. Has it got to do with our Kua number when choosing the color, size and combination? Need your professional advice on this.