Acro coloring issues is a very tough nut to crack, I don't think anyone knows the secret sauce or they will be millionairs selling that sauce. Even pro coral sellers sometimes get healthy colonies that within a few weeks of introduced to their system, have colors shift completely from yellow/blue to pink/green. This is part of the challenge and fun of keeping acros.
Color issues comes in 2 types -
browning/bleaching points to more of issues with the "baseline" minimum requirements - water params (ph. Alk, ca, mg, no3, po4) temperature, sufficient par, and flow. It seems at least you have a good understanding of this so starting off, make sure you have all these within a stable and acceptable range. From what you posted, your salinity need to stabilize, can't have that big a swing bc that will swing the rest of your params. Shoot for 1.026. Alk is a bit high but not problematic, shoot for 9 if you can. No3/po4 can't be 0, bc then you won't know if your tank is deficient, so we always want to have a little bit of measurable excess. Anywhere from 1ppm to 10 ppm no3 and 0.01 ppm to 0.05 ppm po4 is fine. You didn't mention PAR. If you dont know what it is, I suggest renting a meter and test. You absolutely need to have a clear picture of your par to be successful with acros. Shoot for 250 to 350 par to start.
Once you stabilize the basics, then comes the hard part of actually getting colors and this is the part thats very trial and error. Consider these areas:
1) trace elements - get an icp test to see of any are deficient. Many of the trace elements influence certain types of colors ( look up red sea trace supp ABCD, for ex)
2) color spectrum of your light - this is perhaps the hardest part, and sometimes there is nothing you can do about it depending on the specifics of your tank. What gives the acros those eye popping colors is not the zooxanthellae concentration (those impacts bleaching/browning), rather, its the concentration of the color flouresence proteins (CFP) that they make. IiRC there's something like a dozen different CFP families for different colors (cyan, green, red, yellow, purple, etc...). What makes it hard is that these CFPs have different peak activation spectrum and PAR. While a number of them share similar ranges found in the typical "blue" light, some of the CPFs peak activations are in the pretty far right red and green range. The issue with just running "blue LED" is that the spectrum tend to be very narrow so you are limited to only a few CFPs activating (mostly the cyan and green ones) which in turn shifts your acros colors more towards green and cyan. This is why many successful acro tanks at least supplement with T5s bc of its broad spectrum. Im not familiar with your light, usually LED suffer this shortcoming but the more high end ones provide different diodes to cover a wider range of spectrum (ie, ai primes have 3 spectrums of blue) Depending on your light, you might want to determine is your spectrum is too narrow.
3) lighting intensity - some CFPs also activate in higher PARs. For ex, i had a "generic" second hand ORA frag that was just a purple stick with nothing special under 250PAR in the old owners tank. Once I moved it to my tank under 350-400PAR, after proper acclimating, it started to express all the pink and greens. Turns out its was a ORA Xmas Mirabilis
Even in two successful and mature acro tanks, the same colony will color shift a bit in the two tanks depending on how different the spectrums are.
