In my opinion, no man should ever wear pastels or bright colors. The ideal color for a man's shirt would be the color of John McClain's wife-beater shirt in the last few scenes of "Die Hard."
I'm always on the look-out for interesting earth tones when I buy shirts for my husband or father, but a typical polo shirt will come in 20 different colors, of which only about 4 are good subtle colors--and those are the ones that are usually sold out! Shouldn't that tell the manufacturer that men (and the women who buy their clothes) don't want magenta or lime green shirts.
What about bright red? I have a bright red shirt and a red and blue striped dress shirt that I wear to work. I also have quite a few orange t-shirts.