The primary use of synthetic astaxanthin today is as an animal feed additive to impart coloration, including farm-raised salmon and egg yolks.[13] Synthetic carotenoid pigments colored yellow, red or orange represent about 15–25% of the cost of production of commercial salmon feed.[26] Today, almost all commercial astaxanthin for aquaculture is produced synthetically from petrochemical sources.[27] While it constitutes a tiny portion of salmon feed (50 to 100 parts per million), astaxanthin represents a major share of the cost, up to 20%.[28]
Class action lawsuits have been filed against some major grocery store chains for not clearly labeling the salmon "color added".[28] The chains followed up quickly by labeling all such salmon as "color added". "...law-firm Smith & Lowney persisted with the suit for damages, but a Seattle judge dismissed [the case], ruling that enforcement of the applicable food laws was up to government and not individuals.