If anything should be an indicator of health, it should be growth. Anyone veteran hobbyist will tell you corals calcify faster under lower kelvin bulbs. An Iwasaki 6,500K metal halide grows corals faster than a Radium bulb of equivalent wattage. And let’s compare coral colors to growth. Some of the notable slow growing acropora are the blue hoeksemai, torts and purple monster. There seems to be a discrepancy between growth and color. A purple monster grows pretty fast under an Iwasaki, but its not going to be a deep purple.
Perhaps we lose growth, hardiness and stress tolerance when pushing towards excessive pigment expression and photo-inhibition. Again, this may not be wrong. The hobby places immense value on coral color. So it may just be a double edged sword.
