Neville ChaimBerlin: Forget the techeiles debate, if you truly aren’t trolling, you need to be informed that nobody allows you to just dye tzitzis any color you want. Even the techeiles folks agree to that.
Wrong. As the Rezhiner Rebbe expalins in his sefer Pesil Techeles, there is nothing wrong with putting on kela ilan (if there is no Techeles), therefore you only have to gain and nothing to lose with putting it on.
Bshtei_Einayim: Chazal tell us it was nignaz.
Although Chazal do tell us it was nignaz, the Rishonim understand that this does mean that we cannot rediscover it through the simanim givenn to us by Chazal, (see for instance Shut HaMahril Hachadoshos siman 5).