For the record, here's the official explanation for red vs white kings:

The ability of a salmon to store carotene in the fat cells is controlled genetically. So a sockeye salmon (red) stores carotene in its fat cells and a chum salmon metabolize it into a colorless Vitamin A. For a chinook salmon flesh color is determined by two genes in a duplicate recessive gene interaction. Here is a list that will help explain this. It comes from an ADF&G publication. The genotype is the combination of capital and small case letters and the flesh color is defined.

AA,BB -red flesh color,
AABb - red,
AA,bb - white,
Aa,BB - red,
Aa,Bb - red,
Aa,bb - white,
aa,BB - white,
aa,Bb - white,
aa,bb - white.

You can see from this that if a dominant gene (A and B) are both present then the flesh color is red.

The genes for white kings are rare in Alaska. A higher percentage is found in the Pacific Northwest.

How red a fish is or just a pink color depends on the amount of pigment in their diet. However, a white king cannot become a red king no matter the diet because the genes controlling the process are not available.

I can't help but think this whole pigment storage defect must somehow be related to the critter's fat metabolism. These kings are extremely oily, esp for a fall chinook. As for that fat, stumpy physique.... a picture paints a 1000 words.