If boys from Meah Shearim or Williamsburg, who never saw a TV or heard a radio or read a secular newspaper, didn’t tell the shadchan that they won’t consider a BT or Ger, who virtually all are familiar with pop culture if not much much more and grew up secular, you’d have divorces r”l before Shana Rishona was over due to major cultural clashes between the spouses.
Same with a Brisker boy marrying a Bukharian girl or a real Yerushalmi marrying a girl from the Lower East Side.
An Ashkenazi seeking to marry an Ashkenazi or a Sephardi seeking to marry a Sephardi is doubly okay. Firstly, it is legitimate to seek a spouse with the same general minhagim as yourself, so you need not change your minhagim. Secondly, there are cultural differences between them that may not be easily adjustable and can cause great tensions.
If hair color or height is a legitimate consideration, the above are certainly far more legitimate considerations.