It seems I've ventured into a little-documented area here in imagemagick/imagick.
I'm using php's imagic - not the command line. I have to convert photos that some experienced photographers take, but it converts the color to a model not consistent with what they had used to make their more vibrant photos.
Example: http://www.picturemojo.co.nz/image/muriwai-gannet-colony-auckland-new-zealand/ That photo is actually twice as vibrant and depthy. But the inaccurate color conversion blandifies it.
