Wow that is weird I just used some the other day ok it last about 2-4 day depends on how you treat it. Like if you take a shower then it will get lighter. And if you so swimming it will get even lighter. So basically water will make it lighter. And it will look orange if you do not spray it on evenly. So what you should do is have some on to do it for you out side and just like spray paint spray everywhere never in one spot. And make sure you don't spray too much because it might drip and make a orange line. So let it air dry and it should be fine and do not wear anything white because it does stain.
I've done that once for fun. It doesn't make you look tan, but I think its a waste of money. Try the bottle ones. (not the cheap stuff) The bottle really helps better.
From what I have seen, most salon spray ons will not make you orange, the lotions and other self tanners have more of a tendency to. Most salons will have an instructional video for you to watch which you should pay careful attention to in order to get an even and all-over tan. If you use the booths, you will only be in there for about a minute but if you are comfortable with it you will get a better job if you ask them to spray you.
Well it depends on the different formulas/brands they use. Also whether or not the tan specialist does it for you or you go into the booth. Usually they last 5-7 days and cost around $25-35. Good spray tans do NOT make you look orange! If you look orange after your spray tan. Obviously it was not done right. The booth spray tans tend to miss areas however, I do believe they are slightly cheaper. Also don't forget to listen carefully to the instructions they will give you, you'll need to wait to take a shower, and not rub your skin or use and scrubs, amongst other things. I think you also can't sweat and not swim (dont go anywhere near water).
Have a lighter one at this time of the year and feel great. :D