The present invention provides a salmon flesh color improving method and a salmon flesh color improving feed which are usable for producing a salmon having a mild reddish orange flesh color close to the flesh color of wild fish, and a salmon and fish flesh thereof produced by such a flesh color improving method. The present invention also provides a method for producing a salmon having a mild reddish orange flesh color, comprising cultivating the salmon with a feed comprising a carotenoid colorant mixed therein, the carotenoid colorant comprising at least astaxanthin, phoenicoxanthin, canthaxanthin and adonixanthin.