Thanks for those questions. I get 1 a lot.
1. Since I am unable to see, my dreams (when I have them) are neither in color nor black and white. I have no concept of color, at least, not in the traditional sense. When I hear the word green, for instance, I only think of things associated with that color such as grass, frogs, and new leaves. When I dream, I experience my other senses but unlike in reality where I can become lost and disoriented, I just know where things are located. Have you ever read A Wrinkle In Time? In that book, Maggie travels to a planet where the creatures do not see at all. Because nobody on that planet sees, sight is completely irrelevant. It's as if sight is a nonexistent sense in the dream world.
2. In some countries, I know that the currency is differentiated by size. However, in the USA where all bills are the same size, I must rely on sighted assistance to determine the bills. After I have determined what I am carrying, I fold each bill differently. For instance, $1 is kept straight, $5 is folded in half, width-wise, and $10 is folded in to quarters. Although there is a standard folding system in use, I have deviated from it. I suppose it's all right as long as I know what I have in my wallet. Coins here in the USA are easier since they are all different in size. Quarters and dimes have ridges which prevents me from confusing them with nickels and pennies.
3. There are several software packages that allow text on the screen to be read aloud. The one I use is called JAWS (Job Access with Speech) and it runs on Windows. I don't have much experience with other operating systems but I believe there are screen readers for them as well. Screen readers are able to read text, alert the user if there are dialogue boxes, tables, and lists. However, graphics cannot be recognized unless they are tagged.
I hope this helped a bit. Please feel free to ask anything of me regarding this subject.