pardon me rabosai if this has been mentioned before, I’m not holding kup in this long thread. Mohnafshoch, green or blue, it is really dark. If we don’t understand Rambam in Tziztis beis, alef, Kpasuch shebekachol, and tahoro shel rakia lein shemesh, we have a clue from Halacha ches: In a talis shekula techeles, the “white strings can be any other color, ‘EXCEPT BLACK, because it looks like techeles (not really distinguishable).
Ken zein, we have established reasonable doubt.