The texture is already aligned perfectly. The black/purple lines you’re seeing are caused by the filtering.
To best maintain the appearance of pixel art sprites and tiles, import them at their original size, use the BGR888 format, disable mipmaps and enable the Point Sample flag.
To clarify: the Point Sample flag is the most important here, since it disables texture filtering. Also, importing at the original size might not give the best results if the tile/sprite dimensions aren’t powers of two. In that case, it might be preferable to scale them up and to use a compressed texture format.