I'm currently in the process of coloring the Pioneers of Geospatial Imaging artwork. I use Adobe Illustrator for most of my initial color and texture work. Vector art is really flexible and allows me to move elements of the designs around easily. Later, I will work finesse the art in a raster-based editor like Photoshop or Manga Studio. I'm also working on a fifth pioneer, Marie Tharp, that I'm excited to tell you more about. Stay tuned.