how to get that purple/ red color

[TimT]

IMHO there are several factors which affect coral colouration; lighting, genetics, zoozantheallae, phosphate and nitrate levels, nutrient and mineral loading of water, stress and food.

I have a very nice neon pink milli with baby blue tips and neon pink polyps. I recently changed out my XM 20k 400w bulb for a 20k Radium 400 watt. The rims of the coralites are now going baby blue.

At roughly the same time as changing the bulb I moved the system sump and consequently the ETSS 1000 downdraft skimmer has been offline for a few weeks, thus giving higher nutrient loading.

So what is causing the colour shift... lighting or nutrient load? I suspect it's a combination of both.

From my experience those pink caps require a lot of light. Mine is hot pink and it sits directly under a 20k radium 400 watt but it also gets natural sunlight. When the sun is shining you cant even notice that the Halide is on. My suspicion is that the coral you have was pink at one time, hence the name, but do to lack of light and other conditions(shipping stress) it has lost the pink color. If conditions in your tank are favourable to it the colour should return.

[Coleus]

I will try to move it to the top and see how it does. Most of my montis are in middle of my tank and has excellent growth.