The Pure ZC database is sorely lacking in well tiles for people to use. Most tilesets default to either the Link to the Past Well tiles, which I find underwhelming, or the Final Fantasy VI Well tiles, which works only in tilesets with styles resembling Dance of Remembrance. So I drew my own and I liked them so much I decided to submit them to the database.
This submission has well tiles for 16 bit tilesets (BS, Pure, Link to the Past, DoR) plus a set of tiles for Gameboy Zelda tilesets.
Each set of well tiles contains an empty well and a water-filled well. In addition the GBZ set has variants of each depending on how faithful to the Gameboy colour limitations you want to work with - One variant is faithful to Gameboy's 4 colours by 8x8 minitile rule, the other is 4 colours + "transparency".

Pure ZC community
Nintendo