That's a picture of my pale grey grout up top. Mixing it up with my drill and a special grout paddle reminded me of making cake batter. The $12 paddle was worth every penny. It's exhausting enough to do these DIY projects, so power mixing, as opposed to hand mixing, is definitely the way to go.
The tile is looking great, but I can't fully appreciate it until I paint the walls. The old yellowy white paint is totally clashing with my crisp white tiles and pale grey grout. I finally decided on Benjamin Moore Gray Owl for the walls, which almost matches the grout and for the trim and window, Sherwin Williams Pure White.
No painting today, though. Tiling has wiped me out!