Some color sealers are like epoxy, where you paint brush (scrub) them into the grout, using 2 coats to build up the finish. This leaves the grout lines slick, without a sanded finish.
The client wanted to retain the sanded look.
We were using a new color sealer from Magic Wand. You mix dye powder with the sealer (which is clear), to the desired color, and then apply just like a clear sealer. We used a small bottle with a brush on the tip to apply the sealer to the grout lines. It seals the grout lines while still leaving the sanded look, and evens out the grout color. Some of the grout lines were really stained with something that wouldn't budge, and the owner had replaced 4 tiles and re-grouted an area, so he was looking for an even coverage.
We used this particular sealer because he had stainless appliances, and even tho we taped them and covered them in plastic, if acid gets on them, the finish is etched and is hard to correct, if at all. This sealer's instructions strictly state not to use acid to clean, as is normal with color sealing.
In the 1/2 through photos, all that had been done was to apply the color seal to the grout lines. Nothing else done to the tiles. The color sealing really makes the color in the tiles pop.
We sold all our heavy, hard to load and unload Tile & Grout Portable and tools. We cleaned this with the tile and grout brush on the 17" Commercial Breeze, the blue tile and grout-line brush, and the $15 Shop Vac that we bought at Wally World on Black Friday. We had the fans already.
We decided not to do large areas of T&G, just kitchens, bathrooms, etc. so we don't need the big stuff.