Ah, yess....Lavender recognition is an early sign of pondsanity.
That lower left fish is from my all male bluegill pond. He's one of the specially selected fish from my little breeding program. That fish is fast growing, and hasn't attained any dominant male characteristics, but I caught what I think is that same fish yesterday morning on a newly built nest. If you were to hold that fish in your hand, you would see the black nape scales (which females never have) and the lavender hue would be more apparent as you turned him a little to catch the sun's reflection. Part of the point of the article, which we may not have stated clearly enough, is that those pictures are to illustrate how similar these immature or late maturing fish are to females. The first part of the article showed the characteristics of the dominant males, which are the ones most people would choose for an all male pond.
Check out figure 3 in the first article. Those are the dominant, easy to ID fish, then look at figure 2 of the second article and those are the toughies.
