Wow, bombshell dress! Well, the style of flats will depend on why exactly you can't wear heels; is it just due to the heel height, or because they pinch your toes/ cause your foot to slide forwards/ any other reason?
If it's just the heel height, then I second Angie's recommendation for a pointed toe flat. Chunky heels are also in at the moment, so you could even find a 'flat' with less than an inch high block 'heel' to wear, if you want to increase the formality factor. I've seen some with metallic heels that could also look dressy.
As for the colour, a metallic shoe could look nice depending on the accessories you choose. If they're gold toned, I'd recommend gold shoes. If they're silver, gunmetal or silver could work. Black shoes would be a bold look & also work as an anchor to the dress - it may be too bold of a bookend if your hair &skin colour is light/ low contrast, though.
If you can't wear heels because of bunions, wide feet or other issues though, then I'd recommend almond toe shoes instead. Round toe may be comfortable, but they'll likely look too casual. D'orsay style (where there are side cutouts on the side of the foot) may be a way to let wider feet breathe whilst still looking party appropriate. Dull leather might look too worklike, as could patent leather in a masculine style (eg brogues or Loafers). A Suede material could be fun!
As for other details, embroidered booties are having a moment right now if you're looking for a more trendy look (eg - club after drinks etc). You could also go for a cross-strap, or caged/ gladiator style (someone posted a photo of similar shoes here on the forum earlier https://youlookfab.com/welookf.....ppropriate ). Be aware that these details may skew 'young' though, so I wouldn't wear them if your dinner is more formal or work related.
Hope that helps!
