Formal Dress?

formal and cocktail dresses are not the same!!

it doesn't matter the color.
but you would want ankle to floor length
if you go strapless have a shawl, it can get chilly in the evenings
if you have any tattoos better to cover them up. You are not hitting the bar on ladies night you know

manners are important so brush up on the table manners, no elbows on table that sort of thing

there will probably be a receiving line--NO drinks in hand in line

For military formal you want to go with something more conservative, with straps, my hubby is in the Coast Guard and many of the people wear black, or darker colors to match the dress blues. If they are explicitly stating "formal" you're normally talking about a floor length gown, although I have opted for a knee length dress before and wasn't underdressed. It's better to be overdressed than under!

9 years ago, I went to the marines birthday party and I was told I could do a short cocktail dress, after being the only one in a short dress, I will never go to another function like that not in a long dress. I would do a simple a-line or empire waist dress that is to the floor. As for color, I think you could wear any color you want, and I always feel more comfortable in something with straps, usually a spagetti strap. If you go black though, you can add color accessories, and if you have to go to this dinner again next year, it's alot easier to wear the same black dress again, than if you wore a loud color like red. I'm with the others on checking David's. But since it is prom season and wedding season, you may have some luck at a department store. Do you have any wedding consignment shops near you, that's another place to check?

If it is black tie you really should wear long (although some people do wear short and it is fine) ...but formal can be both. Here is a link to Nrodstroms formal dresses. They have such a great selection IMO in all price ranges.
.
http://shop.nordstrom.com/c/womens-dresses/evening?origin...

Find something that you will feel comfortable in and not feel conspicuous. Since you are not a formal type of girl, I would say stay away from stiff fabrics, anything tight, or anything over embellished.
Dillards has beautiful dresses, especially for "woman of a certain age". I am on a tight budget, so, I usually go to Ross, Marshalls, TJ Mazz, or Dots and have bought some outstanding dresses on the cheap.

Davids Bridal has the CUTEST cocktail dresses on sale right now. A sales associate will be able to guide you in the right direction. I had to go to a black tie event for my FIL one time, and the saleslady picked a dress I never would have chosen by looking at it on the hanger. I looked like a million bucks, and never would have been able to do it without her!!

I second David's. I went in for a fitting for my SIL upcomming wedding and was so amazed at all the selections - some right off the rack?!
The "new" length (per the 'bible' aka InStyle) is mid-calf and for formal evening event (after 7 pm) you'll want a longer dress:) But honestly - whatever you are most comfortable in is best.
Colors - can't go wrong with black, but everyone wears black, maybe a sage green or a beige - whatever looks good on your skin tone.
Sleves/straps are open to your choosing. Have fun!!

If it is in the evening and it is formal, you should wear floor length and/dark colors. If it is formal mid-day, you can wear short length and light colors. If it is cold, you should wear something with sleeves. A high heel shoes is needed (sometimes with straps)

Since it is a military dinner, you might want to find an outfit that would mimick military appeal so you match with your husband's attire.

Military Balls = Red Carpet Dress.

Google Image Marine Corps Ball, or Navy Ball, Air Force Ball, to set your mind at ease. They are very, very formal. Putting on the Ritz (dress, jewelry, hair, makeup, heels).

The prom dress section or the ball gown section in department stores (macy's, nordstroms, etc.) is where you're going to find what you're looking for in general, although there are boutique stores as well.

At many of the dances now the "formal" is what you would wear to prom. I have been to many a military dance where the younger girls wear the short dresses with halter/spaghetti tops.

Your best bet is a deep color, navy, maroon, black, all Marine Balls are in the fall so mine are dark colors
In the spring I guess any color goes, what color is his uniform? Gold looks really nice against the Army Green. Red looks good with the Marine Dress blues.

Mine are:
long black sheath dress with a maroon lace overlay, short sleeves
a long black velvet with puffy taffeta sleeves and bows,
a maroon velvet fitted long skirt with a taffeta/satin porttrait colored top, 3/4 length sleeves
Typical navy blue prom dress, long, with pearl halter/spaghetti straps
Black full skirt with white lace bodice, long sleeve, satin
Fitted deep purple velvet with a chiffon train attached to the shoulders, sleeveless but covers the shoulders. Train goes only to the end tip of the hem. Pretty much backless.

Shoes: something you can walk in. Black patten leather works with most or a white sandal.
Get a pedi if you wear sandals

Jewely, if the dress has pearls go with pearls, if the dress is a sparkly one then go with diamonds, Claire's or Fancy Q has a ton of prom wear out now.

Shop:
Bridal shops
high end thrift stores--2 of mine cost less than $20
check the mall but Belk's doesn't sell prom dresses anymore.
Macy's has had some really pretty ones in the past

Not places like Deb-these tend to be cheap looking, pretty if you are16 not 32.

Have a great time

Go to a nice consignment store in your area and pick up a (nicer/classier) prom dress or bridesmaid dress. Full length, high heels, formal hairdo and make up. AND have fun being a 'princess' for a day!!