What to wear over a sleeveless royal / Azure blue dress??

[onanothertrain]

I have a blue lace sleeveless dress to wear to a wedding in March. I'm presuming it'll be a bit chilly and I've got fat arms so wondering what colour to cover up with. I have pink, green, navy and white in my shoes.
Any ideas of what would go?

I’m not sure I’d just want a cover up in March! I’d wear a well cut coat! Navy blue, preferably waisted, and wow with a hat!

Failing that, a jewel coloured emerald green jacket. Might be hard to find though.

The ceremony and reception are in the same venue and I'm staying there so might feel a bit odd with a coat on. I was thinking of navy though and do need a new coat...