The original UI lacked many design fundamentals to allow a better user experience. Many different fonts were being utilized, colors were washed out in outdoor situations, there was no contrast between elements to allow for visual hierarchy.
Keeping the font simple in both headers and body copy, allowed for better readability. The darker blue font allowed better contrast in outdoor situations. The splash of accent colors of purple, orange, and other brighter colors allows quick visual understanding of what actions should be made and how to accomplish a task.