Aruch Hashulchan Orach Chaim Siman 9 Seif 12

The punishment for neglecting the white tzitzis strings (lavan) is greater than for neglecting techeiles, since lavan is easily obtainable. Techeiles, being rare and expensive, carries a lesser punishment when absent. Due to our exile, techeiles has been lost, and all our tzitzis are white. However, the mitzvah remains fully valid, as techeiles does not invalidate lavan.

In recent times, someone claimed to have rediscovered the chilazon and produced techeiles, gathering some followers. However, he was not accepted by the Gedolei HaDor or Klal Yisrael, and the matter was nullified—until the coming of Moshiach, bimhera beyameinu, Amen.