Website: u4graphics @ GitHub
Josh Steele’s 256-colour alternate grachics for xu4.
Josh Steele drew up this alternate set of tiles for Ultima 4 a few years ago, first in 16 colours, and then again in 256 colours. Apparently, it has enjoyed use in a few fan-made games, but he has only recently released the set publicly.
These graphics requre xu4 to use.