Add color extraction functions

[oubiwann]

• Create utility functions for:
  • getting the list of color names from the managed color file
  • getting the list of RGB colors from the managed color file
  • getting the list of hex colors from the managed color file
• Create a function that gets a list of all unique colors from an image
• Create a function that will create a color file with colors pre-populated and placeholder names given

[oubiwann]

Done!