BRS Pukani Maturing Or Something Else?

Tank will be 3 months old in the next few days. 57 gallon with aprox 10 gallons of water in sump with chaeto....tank has 50lbs BRS Pukani rock and 10 lbs live rock from 2 different LFS's, 30lbs of live sand from BRS.....cured BRS rock 2 weeks in separate container with heater, return pump, and did 5 gallon w/c every other day, pulled out rock and rinsed it off.....cure and rinse did not use ro/di water(probably a mistep and cause for some hair algae outbreaks)....filled tank with water from 5 Stage ro/di that I bought from BRS, added salt, heater,sand, skimmer and ran system for a day prior to adding BRS rock....let everything run for a week and went and got the live rock and also added a bottle of bio spira, waited 2 weeks and added first livestock........fast forward to now. Rock was originally white, but has been slowly changing to bright green to dark green with brown spots, tried scratching brown off but it doesnt come off with nail....test nitrate, ammonia, nitrite and phosphate daily with api masterreef kit and all test out at 0...use redsea nitrate and phosphate test weekly and only detect about .02ppm phosphate. live stock includes black ocellaris, orange spotted goby, royal gramma, 2 cleanershrimp, sandsifting star, crocea clam, frogspawn, 10 hermits, 10 nassarius snails, emerald crab. sg at 1.024 temp 77 deg. lights coralife 150w hqi mh, 2 65 w actinics, 2 moon led. mh on from 11am - 9pm, actinic on from 10am -10 pm, moon led 10pm-10am, 6k led flood lamp in sump for chaeto reverse cycle from mh....does this look typical for rock becoming live or does it look like an issue that needs to be addressed, havent ran into any problems...see some purple pink and red coraline spots here and there but nothing taking off yet...photos are from 1 month and close to 3 months

 

The term "live rock" is used to reference the point at which the rock is well enough colonized with nutrifying and de-nutrifying bacteria to convert ammonia to nitrite and nitrite to nitrates completing the nitrogen cycle.

Per your description and images, the rock is exactly where is should be at 3 months.

 

looks normal to me. It may also begin to turn grey, pink, purple, or green.