Congrats, getting water is certainly a landmark moment!! The muriatic acid doesn't clear up the plaster dust, it is to keep the PH down during startup. Fresh plaster tends to drive the PH up and you have to add acid now and then to get it back down again. Hopefully they mentioned to you to clean your filters every 3 or 4 days for the first couple of weeks, that plaster dust really clogs up the filters. I can't tell much from your picture, but if you have white residue then the PH may have gotten too high before the brushing removed the cream from the surface. If that is the case, you may want to lower your PH (below normal) and brush some more until it goes away. You might ask the plaster guy about this when you talk to him. Below is a link to a closeup of our pool with medium grey plaster (it's actually a picture of the mosaics, but the only one I have that kind of shows the mottling). Beyond the bench you can see some of the natural mottling, hopefully this will give you an idea of normal mottling versus problem areas. Personally I find the mottling in colored plaster to be very attractive! It's something of a marbling effect. Here is a link that might be useful:

Hey, my pool was just plastered(white)two weeks ago and is already looking mottled/dirty. Is this normal? I have been brushing the entire pool 2-3 times a day and trying my best to keep the chemicals in the correct range. Any suggestions? Thanks much!

We had Cool Blue Diamond Brite installed about 12 days ago. So far it seems fine (See Pictures below). I'm not sure what "Mottling" is but I've seen what looks like streaks or marbleizing on other pools with darker plasters (the ones where the actual plaster has a base color in addition to the aggregate colors). We chose cool blue because it was based on a white plaster. It has mostly white aggregate with some blue, gray and clear quartz. For those debating the proper installation and exposure methods, the details are in SGMs installation manual: sgm.cc/download/installationmanual-DiamondBrite.pdf Read the section on exposure starting on page 6. There are 3 methods of exposure and depending on which method is used, it could result in some streaking. I can't remember if process "A" (water washing with a brush) was done with our pool but I know the installer used process "B". The pool start-up continued with process "C". During the installation I can remember the plaster guys started wearing foam shoes but I don't remember if they were water washing with brushes (process A) at the time. Here are some pictures of the Cool Blue Diamond Brite Installation: This last one is in the shallow Baja shelf area.

Given what sounds to be a formal setting and not wanting the "pond look" on cloudy days I thing a 100% white quartz finish would be ideal. The surface would be white and could be polished providing the smoothest finish. Polishing done correctly with a water driven polish unit, not sanding pads hooked to a weed wacker. The polish part alone should take 5-6 hours. Just my opinion though.