Yes, there could be.
As someone who has spent many many hours researching the issue and has given a few Shiurim on the topic, I will say that there are about as many convincing arguments that the Murex dye is NOT Techeiles as there are that it is indeed Techeiles. (As an aside, this topic is almost Trump-like – it is very difficult to have a dispassionate discussion with knowledgeable people on the subject. Either you’re a Kofer is you don’t believe it is Techeiles or you’re a Kofer if you do.)
Therefore – and I heard this directly from R’ Moshe Shternbuch Shlit”a – while it is true that one may wear colored Tztitzis threads, this is only if he is not Mechaven to be Mekayem a Mitzvah. If one wears the Murex threads believing them to be Techeiles and to fulfill the D’Oraisa and it turns out that they are not (and they absolutely CANNOT be according to ALL Rishonim), then he has transgressed Bal Tosif. (BTW, since there is no Mesora, there is def. no Bal Tigra here.)
R’ Shternbuch holds that even if one is aware of the issues, then he ought not to wear this Techeiles since he will be Machshil others in thinking that it is Vadai Techeiles, leading to a Cheshash Bal Tosif. He conceded the point that there is no reason not to wear them B’Tzin’ah as long as one does so only Al ha’Tzad.