What to wear to a funeral?

I’m not looking for a simple answer as in ‘dark colors’ or ‘black’, I know that much. I’m fifteen years old and I don’t want to look to casual or wear something that doesn’t fit my age. If anyone can give me some ideas (or general pictures of things to wear), that would be awesome.

And don’t forget the shoes!

What size should I get these Topshop boots in?

http://www. topshop. com/webapp/wcs/stores/servlet/ProductDisplay?beginIndex=0&viewAllFlag=&catalogId=19551&storeId=12556&categoryId=98415&parent_category_rn=42358&productId=384764&langId=-1

I’m usually a US 6 in shoes that you wear without socks. With boots and sneakers I’m a US 6 – 6. 5.
Are Topshop shoe sizes larger/smaller than usual? What size should I get – 36 or 37??

I have an emerald green chiffon gown – what is the best colour for accessories to go with it?

I bought this gown because I fell in love with its colour, now I have a ball coming up – I don’t want to accessorise it with gold shoes and clutch because I don’t want to look like a christmas tree. . . or might it work? I have no idea what other colours might look good on it! Any suggestions?? I am a brunette, in case it might help. Thanks a lot everyone!!