Black & White/Black or White?

[NZRoadtrip]

I'm going to the races in Brisbane on 1st June, the dress code is black & white and I'd planned to wear my favourite black wrap dress, black strappy shoes, black handbag and black fascinator. I was showing my friend my outfit last night and she said that it doesn't fit the brief as it's not black AND white, is she right, do I need to wear both colours?

Another question is what colour nail polish for fingers and toes you'd wear, would you go understated like pale pink/nude or would you go for a splash of colour?

Google is no help but I think I'd go for black and white.

So far as nails, nothing. I never paint my finger nails and I wouldn't wear open toed shoes to this.

Paint nails white, add a big white flower corsage or white wrap.