Navy. It will look better with your coloring and you can wear brown or cognac shoes with it and bookend your hair.

I'm going for navy because it's the softer and friendlier colour and I know it's flattering on you.

Seeing as you already owned a black one, I'd suggest mixing things up and going with navy. I'm a big fan of navy in general.

Navy is in the lead. I still think Gaylene and others have made valid points about the black. It's late here, so I will sleep on it:)

Because you are replacing a black dress I wonder if you will miss it if you don't order the new dress in black? Can you return easily? Maybe if you order both it will be easier to decide depending on the shades, sheens etc.

If you could try them both on, that would be great.
There are all the hypothetical issues above, but sometimes the IRL test shows a clear choice--the sheen, or lack, the depth of color. The blue which is not classic navy might be a better blue for a summer dress, or might read less luxurious. The black might look harsher in person or might really "pop" with your accessories. It becomes not a black vs. a blue dress but what does THE dress look like when outfitted.

Black for sure Ingunn. I think black shirtdresses are so chic. Go for it!

I vote black but the navy is lovely too. I'm really loving the one you are thinking about letting go. I like the sleeves!

OK, the comments are making my head spin! I haven't read them all. But I did see where you said you would probably wear it in the summer. That makes me think that navy would be a better choice. Although I do wear black in the summer, I think that a solid-color day dress that will be worn in the summer would be better in navy than in black. Black seems too heavy a color given the weather and the daytime nature of the item.

Wow... This is hard. I want to say navy so badly, as I am so into navy right now, and it would look lovely on you. But I have to vote black. The only reason is because I think you are more sure of the black. In such a close tie, you have come up with two reservations about the navy (brass buttons and potential for sweat stains) and none for the black. Also, your voting buttons are set to yay for black and nay for navy. Just sayin'....

I vote for black.

I'm voting black,but either would be lovely on you. FWIW, I have identical black and dark navy sheath dresses and the navy is the better color on me. But, the black one gets worn about 10 times more than the navy. It's just easier to style and feels more elegant. It's easier to pick up a jacket or accessories for black.

Sage Gaylene nailed it again.

Black

I'm voting for navy because it'd be unique! Especially because navy is a great spring/summer color. You can easily make it look classic or modern, go for the nautical color combos that have been really popular, or brighten it up with some fun colors.

I'm voting black! For all the reasons Gaylene shared:)

What unfrumped said. Can you try both on and post pics?

I don't know what suits you better but usually black & navy are similar in how they look on. It sounds like you have shoes in colors to go with both. I vote navy because I think it is less harsh in Summer during the day. It is a daytime dress right? Or casual evening. It is easier to find black dresses than navy so I would lean towards navy.

Darn! I would like a true ink, darker navy one. The one non black here it's more of a medium blue to me, which I don't care for, too much-and then, I would rather buy the black one:-(. But picties aren't always true to reality, so I vote try them both.

Honestly if you could try both on I think you would make the decision easily. One would be more magical. Is that an option?

Ack! I wish I could try them on, but that's difficult. I'm going to order it and have it sent to a hotel in France where I'll stay next week. I could order two and return one, but I'd rather not.

Lots of good points here so it's a tough call but I've got to say black.

Hmm, if it's an expensive item and you're really not sure then I'd say order both. I think the cost of return shipping would be worth it.

I'm still at a loss! It's hardly ever been more difficult to pin a color. I think I have to take the bite and order both after all.

My next worry is the size. If the measurements on the website are correct I should take a small. However, I don't want it to be too tight. My two shift dresses, that are a little roomy around my chest, have the same measurement. That should give some indication that it's the correct size for me, right?

My gut feeling tells me that this much back and forth seldom makes a good purchase. I think I'll keep a shirt dress on my long term shopping/wish list and stick to what's in my closet for now.

I think… is this a good decision?

I have to agree - unless you can easily try them on this seems a bit risky, especially if there are taxes and shipping costs involved.

I think it's a good decision. There are so many shirtdresses available right now. Buy from a B&M store where you can try it on.

Absolutely! I believe that there is plenty of time to find a beautiful dress...one that will be perfect for you!

Yes, you are right. The right dress will turn up, and I might very well have been wearing my sales goggles after all. Thank you for sorting this out with me.