When we got married we looked at the romantic castle idea, then it became apparent that it was our choice to want to get married here, so in all fairness with it being so far away, we would have to pay travel and hotel expenses. How etiquette has changed in over 15 years.
We honestly would have never said come to our wedding in this grand castle, oh by the way it's going to cost you travel plus 2 nights at least. But more likely 3 to offset the travelling.
We were onto B&B's and hotels nearby, it was totally lovely, it had a tradition too, due to the location the actual wedding breakfast for 5 courses was very fair. Then reality struck and in all fairness we would have to host a meal the night before, the wedding breakfast, the evening reception. Whilst financially it was viable, we found a pub that was lovely but seldom had custom apart from a handful of regulars. We were happy for them to come and tuck into the buffet, we got the venue for free, it was sooooo much cheaper than the really romanticised version we had initially planned.
Also found that because it was on a lower budget, not intentionally, the day rolled out relaxingly, over having a timed affair. It was so chilled, I remember being in pain, taking my shoes off and semi reclining into hubbys arms. That was the best picture of the day too, me looking up at him and us both laughing.
Sorry for my story there, but I find it outrageous that she is being princess for the whole weekend and you have to pay.
I would make out that you'll find something else but arrive in your dress anyway. She'll just hop up and down in bridezilla rage till your Mum coerces you to buy a different dress. If it's in her colours so what?
I've never heard of a bride apart from stipulating dress code, saying oh and no one to wear this colour by pain of death.