No, you may not wear a dark blue shirt and black slacks to a black-tie optional event. Even though the black tie is "optional", it still indicates that guests should wear very formal clothing. It is likely that many of the guests will be wearing tuxedos, but a dark colored suit preferably black) with a crisp white shirt and a darker tie are still appropriate. At the bare minimum, you might be able to blend in without the jacket, but it is best to wear the full suit. Ultra formal events, which are rare in America, are "white tie formal". This includes things like the Inaugural ball for the President. Just below this is "black tie formal", which includes things like the Oscars. "Black tie optional" is just below this distinction, so these events are still considered very formal. Hence, the need for the dark suit if one cannot wear the tuxedo. For more information see this wiki post: http://wiki.answers.com/Q/What_does_Black_attire_mean
Yes, etiquette permits women to wear slacks (nice top and jacket to go with the slacks) and a little jewelry to a Chinese wedding.
It really depends on the weather, and if it is a formal or semi formal wedding. Plus don't wear black ones if you do wear slacks wear cream, or color......
It is either black tie or optional, but generally it is not both. On the safe side the woman can wear a pair of nice slacks with a fancy top and some dainty jewelry; a dress (any color, but white) such as a cocktail dress (in black or other colors) with a little jewelry and some nice shoes.
* If you are not part of the wedding party then yes, a nice sports coat, well pressed good slacks; good shirt and tie with shined shoes is appropriate.
* If it were a black tie wedding then it would be announced in the wedding invitation. Since you haven't done this leave it up to the individual guests as most of the men will wear different colored ties; some with sports jackets and slacks; suits or perhaps just slacks and a shirt with a tie. If you are having a very casual wedding then you could mention 'casual dress.' However, the first suggestion given is generally the best.
If you are male and not in the wedding party then yes, you can wear a blazer, but a sports jacket would be more fitting for the event. If you are female then blazers can be worn with slacks (if not in the wedding party) and dressed up with jewelry.
Yes, a female can wear a white shirt or any other top as long as she is not dressed in all white and has a contrasting color such as blue skirt, spring slacks, etc. Bruh..... this is a diff. person by the way that was able to edit your answer...girls can wear whatever they want to a wedding, it's THEIR wedding, not yours.. -_-
Go for it. As long as you're not wearing ALL black as a protest statement, anything goes nowadays.
Men can wear black; brown; blue; pin stripe suits or a sports jacket in a mocha color (coffee/cream color) and slacks to suit the sports jacket, with a shirt to go with the sports jacket and a tie. The shows should match the suit or sports jacket and slacks (example: blue, black ... black shoes; pin stripe with gray in it or blue can be worn with black shoes; but, brown suits or sports jackets with brown slacks (including mocha color) should be worn with brown shoes. If you do not own a suit; sports jacket or slacks and do not feel you will get much wear out of it then you can go to a wedding rental shop and rent everything.
* Unless the bride to be has printed 'casual' on her invitations (example: garden wedding with BBQ to follow) then no, all weddings, no matter what time of the day or evening are generally formal weddings and one should dress to fit the occasion. For the men it could be a pair of nice dress slacks, belt, shirt and tie and a sports jacket. For the women it can be dress slacks, nice top and a jacket (or no jacket) to a skirt or dress.
If you are a female, I would suggest a skirt or dress that goes to the knee or lower or some nice dress pants. If you are a male I would suggest slacks and a button down collared shirt with or without a tie. Try to wear something that is a subdued color or pattern, nothing to bright and flashy. Don't try to draw attention to yourself, it's supposed to be on the happy couple!
Slacks are casual pants that are a little dressier then jeans.