Integrate velocity coloring

[sfogarty]

• Encapsulate that process in R
  • Define object interface
  • Build object
  • Have the object accept functions that return colors (Find unique colors and replace with integers)

Thoughts for interface:

• Take a function of (x,y) and f(x,y)?
• Just have parameters for "xCol" and "yCol"
  Probably start with the later, generalize to the former if we need to.