Updated the keymap upgrader to highlight which lines it changed as well
as indicate when nothing needed to be upgraded.
Also adjusted the line highlight colors to be more readable in both
light and dark color schemes.
Previously the colors of operating systems were the same both for dark
and light color scheme. That's not a major issue, but adjusting the
colors for the dark theme to better match the theme looks like an
improvement.
Colors were just darkened by reversing the lightness of each color taken
from the dark theme.
