First, I'd scrap all the silicone caulk. You'll beed to hit a hardware store, and pick up a silicone residue remover, otherwise no caulking will stick-- not even more silicone. Once you've cleaned it up, you might want to go to Lowes and take a look at their selection of Laticrete caulks. They're made to match their grout colors, but I'm sure you could find one that comes close to yours (unless yours is white, then it'll be a dead ringer!). The reason I specify the Laticrete caulks is that they have antimicrobial agents in them to help stop the growth of mold and mildew.

for a number of reasons, i wouldn't worry about the mastic (that might take a long time to dry out). one can now safely add mastic into the large gaps, between tiles, and leave room for grout to be added later. The Main Thing here is to make grouting easier and more likely to proceed trouble-free and give good results, that you will be satisfied with. Only a DIY can do this. A pro would not come back for one more little step when they could finish it all off in one go. So, this is a happy time, for you. You get to do a better job than a pro might do. Be happy. Don't worry.

If the installation is only a few days old, additional grout can be added over the existing. If the existing grout has cured well, and you're only adding a thin veneer of grout (thinner than the joint is wide), it's somewhat risky in that if you don't get a good bond, the new grout can flake. If the grout is well cured or if you want to increase your odds, the existing grout can be taken down a bit. A grout saw powered by elbow grease, a cutting wheel or a diamond bit on a dremel, or a cutting wheel or angle grinder...your 1/8th inch widths make this difficult. The most laborious, but the least likely to damage the tiles, would be a hand held, elbow grease powered grout saw. Take the grout down a bit, best bet it to make the joints as deep as the joints are wide. 1/8th to 3/16ths inch deep. Add new grout, this time the installer shouldn't be so aggressive in cleaning the joints. A light touch going 45-degrees across the joints is all that's needed. It'll clean the tile yet leave the joints fully packed. Pits in a cut edge can be painted, an epoxy paint works best in my opinion. If the grout is a color similar to the tile, the pits can be filled with grout and they will blend. If the grout is a contrasting color, grout-filled pits will stand out like a sore thumb, accentuating the raggedy edge. Sealers will not build adequate mil thickness, as most are penetrating and not surface sealers, so they won't fill the grout joints. Sealers really can't be colored, as they are usually transparent and don't create an opaque film buildup on the grout surface. They can be tinted, but it's a transparent coloration, not a solid body type of color. Most sealers are colorless, but there are grout colorants (Aquamix being my favorite) that is a colorant and sealer. If you wanted to go that route I'd get in touch with Aquamix's tech department. You might be able to get some thickness build out of the product with one or multiple applications, it might be able to fill the grout joints and cover your exposed tile edges. I'm not certain though as I've never used it in that manner. But it is an excellent colorant. Do be aware that the Aquamix grout colorant is an epoxy-type film, it sits on the surface of the grout. Best bet is to regrout and to not overwork the joints when cleaning. That will give you your original grout/tile look, preserving the original design. All that being said...rectified tile usually has a perfect 90-degree edge, so if you're already seeing the tile body color on the edges, the grout joints might already be 1/8" shy of the tile face. In that case you should be able to just add new grout over the existing without having to do any joint preparation. My opinions... Mongo

weedyacres- LOL! That was actually something we were talking about when I wrote the post. I originally intended to install chrome wire corner shelves, but we never got around to it becuase we knew we were going to have to rip the whole thing out, so we just lived with them on the floor. Looking back, I think that I would prefer a niche to the corner shelves, and I plan to incorporate one or two in the new design.