I have a maxi dress for a wedding but it has a very deep v neck at the back and front. I don't fancy flashing anyone (for their sake 
eeeek)! So I was thinking of buying a cami to go underneath it. I just wonder if this will make it look a bit too casual? It's not a terribly smart wedding as it will be abroad and somewhere requiring flat shoes according to the invite.
The dress is mainly black with some orange, lime green and coral bits on it. Any ideas much appreciated.
I also thought about asking a tailor to add panels, but it might end up costing me more than the dress did, so not sure.