What colour cardi or jacket to wear with this dress?

[Joltek]

I’ve bought this dress to to wear to a wedding next weekend, I’m now worrying it seems a bit casual but think it will have to do but I will need something to cover my arms as the weather doesn’t look great. Would you suggest a short or long cardigan or a jacket maybe? What colour? I’m clueless so thanks for any help.

Not a cardigan, that would make it look really casual.
What colour shoes & bag are you wearing with the dress? That might depend on what jacket to wear

I've a wedding next month and have been looking for a jacket. I thought there was a good selection of reasonably priced cardigans and boleros on the Hobbs website. I can't tell if the base colour of your dress is blue or black, but this comes in a range of colours.
https://www.hobbs.com/product/carrie-bolero/0223-9084-1124K01-IVORY.html#cgid=occasion&is=false&sz=60
I agree that you should coordinate the jacket/cardigan with your bag and shoes.

A jacket in that red, rusty colour, or yellow. It might be difficult to match, though.

As soon as I saw the dress I pictured it with a cropped white jacket

It's a pretty dress. Don't spoil by putting a Hobbs wedding guest bolero on top.

As it's Nobody's Child I had a look on their website.

This is the perfect shape but not pattern
Nobody's Child 1

These might be possibilities
Nobody's Child 2
Nobody's Child 3

Or one of these?
Nobody's Child 1
Nobody's Child 2

Oh fgs links are useless

https://www.nobodyschild.com/products/butter-yellow-tailored-blazer-o251799ylw?queryID=1891e9bacb1c4624c68094e0ebc6b016

Or a Whistles jersey jacket? They are very good over dresses. Or the Marie casual jacket- which isn't that casual.
www.whistles.com/clothing/coats-jackets/?cq_src=google_ads&cq_cmp=21819885019&cq_term=&cq_plac=&cq_net=x&cq_plt=gp&utm_source=google&utm_medium=cpc&utm_campaign=21819885019&utm_content=&utm_term=&gad_source=1&gclid=Cj0KCQjwnui_BhDlARIsAEo9GutIwoDqSbaMupoXikWj_A2210_MnTx57cX8TtBLKa5ESrQRoV7T5roaAimaEALw_wcB