Witch outfits are not supposed to be pink. They are supposed to be scary. Noone is scary wearing pink.
Freddie Krueger in a frilly pink tutu - not scary.
Michael Myers in a hot pink shirt - not scary.
They are also not supposed to be flouncy, off the shoulder ballgowns. Strappy dresses are not for little girls. I've yet to see a witch outfit a boy could wear, and why can't a boy be a witch? If a girl said they wanted to be a wizard I'm sure that could be arranged. And who the heck thinks that wearing a nice strappy faux bodice out in the tropical temperatures of the English climate Hallowe'en night is a good idea? Especially for a young child? I suppose you could put a coat on them and ruin the costume. Or you could just hope that the sugar intake will keep them moving fast enough to stop them from freezing.
Girls can wear pink the other 364 days of the year, indeed with the pink monopoly on the 'girl's aisle' of the average clothes shop, it's almost mandated. Don't dilute Hallowe'en with a pink rinse. I'm sure even the most precious little princess can cope without a pink skirt for one evening.
I saw an article the other day entitled 'How to take the scares out of Hallowe'en for your toddler' Take them OUT? I'm dreaming up scares! Aren't they the whole point?! OK, I may have put a fake rubber arm up my sleeve and asked my toddler to hold my hand in the Hallowe'en aisle in the supermarket the other day. When my arm fell off she was freaked. I thought it was hilarious. So I might not be the best person to ask.
Oh, and whilst I'm on the subject - Mrs Claus outfits for 3 year old girls, pom pom drawstrings and faux bodices - that's obscene. For God's sake just get them a Santa hat and a nice red jumper.