Painting Dry Rock- Need Advice

Will pay someone with DIY experience in similar project to paint these 2 pieces.. I have 100 lbs of dead coral that I've had for a long time and it is bright white. I have to bleach every month as it is in a fish only system. I would like to paint purple but do not know what type of paint to use. I would like it to look like aquacultured live rock, it does brown out after about a month or so. Has anyone ever painted any base rock or white dry rock? Basically I would like to paint so I only have to brush algae off periodically and not bleach, if this was a reef tank I would just let coralline grow on it but that is not the case.

there are products out there that kickstart coraline. Fish only or reef doesnt matter

Thanks, I've tried it but very hard with fish only, tried purple up, water changes, tried for many months- just don't have the lighting for it..

I have a 400 gallon tank that stands 36" tall. I have one 48" current orbit amd two 48" led lights for supplemental lighting and I grow coralline no problem. There are many different types of coralline. If you have low light then go to a LFS and get LR rubble with coralline on it from a sump and introduce that into your tank along with purple up. You must have coralline present already for purple up to work. It won't just make it appear overnight.

My advice is don't do it. Chemicals and the algae will still grow on it. You would be smarter to go and buy live rock.

I have generally just ground some coraline(quickly and with some water= less air) in a bowl, Put the new rock in a bucket with algae suspension with an air/water pump for a day or so. comes out reddish purple and nature takes its course. no dosing.