Stay away from kitchen tiles. Contrary to backyard expert opinions, kitchen tiles become very dangerous when they break and end up having edges sharp as razor blades. We have renovated dozens of pools that originally had kitchen tiles. 80% of the time the main complaint was getting cuts. One little girl need 9 stiches.
Better still check out PebbleCrete (Quartz crystal based). Best and hardest surface on the market. 100% natural product and gets better with age. No more regrouts. Low maintenance and 5 yr product warranty. PM me for details.
This is a pool tile.