definetly both rainbows, and the white meat is due to diet and post spawn. the natrual feed in the lake is different from that in the river and the strain on the system some time cause the dicoloration of flesh due to diet . see below
Wild rainbow trout that eat scuds (freshwater shrimp), insects such as flies, and
crayfish are the most appealing. Dark red/orange meat indicates that it is either an anadromous steelhead or a farmed Rainbow trout given a supplemental diet with a high
astaxanthin content. The resulting pink flesh is marketed under monikers like Ruby Red or Carolina Red.
Steelhead meat is pink like that of salmon, and is more flavorful than the light-colored meat of rainbow trout
In the wild or on the farm, the color of a trout's flesh depends on its food supply. A naturally occurring pigment called astaxanthin, found in many crustaceans, accumulates in the flesh of salmon and trout that eat them, and this pigment is the source of the orange-red color typical of salmon. Wild rainbow trout in fresh water eat a mixture of insects and small crustaceans, which gives the meat a light pink color. Their seagoing cousins, salmon and steelhead (the latter a rainbow trout that has migrated to the ocean), eat a higher proportion of crustaceans, mainly small shrimp and their smaller relatives called krill, and have resultingly darker orange meat.
The vast majority of farmed rainbow trout get a diet based on grain and fish meal, and they have pale-colored meat that cooks up to an ivory color. But if you feed them salmon feed, which includes a synthetic form of
astaxanthin, the meat takes on a typical salmon color, and to my taste, a slightly fuller, more salmonlike flavor as well. Most Western trout farms now produce at least part of their crop in the salmon-colored form, sometimes labeled "steelhead" even if they have never seen salt water.
Determination of astaxanthin stereoisomers and colour attributes in flesh of rainbow trout (Oncorhynchus mykiss) as a tool to distinguish the dietary pigmentation source.
The presence of carotenoids in animal tissue reflects their sources along the food chain. Astaxanthin, the main carotenoid used for salmonid pigmentation, is usually included in the feed as a synthetic product. However, other dietary sources of astaxanthin such as shrimp or krill wastes, algae meal or yeasts are also available on the market. Astaxanthin possesses two identical asymmetric atoms at C-3 and C-3' making possible three optical isomers with all-trans configuration of the chain: 3S,3'S, 3R,3'S, and 3R,3'R. The distribution of the isomers in natural astaxanthin differs from that of the synthetic product. This latter is a racemic mixture, with a typical ratio of 1:2:1 (3S,3'S:3R,3'S:3R,3'R), while astaxanthin from natural sources has a variable distribution of the isomers deriving from the different biological organism that synthesized it. The high-performance liquid chromatographic (HPLC) analysis of all-trans isomers of astaxanthin was performed in different pigment sources, such as red yeast Phaffia rhodozyma, alga meal Haematococcus pluvialis, krill meal and oil, and shrimp meal. With the aim to investigate astaxanthin isomer ratios in flesh of fish fed different carotenoid sources, three groups of rainbow trout were fed for 60 days diets containing astaxanthin from synthetic source, H. pluvialis algae meal and P. rhodozyma red yeast. Moreover, the distribution of optical isomers of astaxanthin in trout purchased on the Italian market was investigated. A characteristic distribution of astaxanthin stereoisomers was detected for each pigment sources and such distribution was reproduced in the flesh of trout fed with that source. Colour values measured in different sites of fillet of rainbow trout fed with different pigment sources showed no significant differences. Similarly, different sources of pigment (natural or synthetic) produced colour values of fresh fillet with no relevant or significant differences. The coefficient of distance computed amongst the feed ingredient and the trout fillet astaxanthin stereoisomers was a useful tool to identify the origin of the pigment used on farm.
hope this helps
chef