Art3d10-Piece Stick on Backsplash Tile for Kitchen, 12" x 12" Vinyl Decorative Tiles

Q: Is the color blue or teal?

The color is blue. Very pretty!

Q: How to.make them stick to the wall with out falling down later

If it is to stick over sleek surfaces like cermaic, glass, plastic, acrylic, it will not fall down for sure. It can stick to a plain painted wall as wall, but to make sure it's clean and smooth, I would say to sand lightly over any kinds of painted wall before sticking.