Teaching myself how to use radio boxes, I created this simple example that allows me to change the color of a square by selecting a different circle. This is inspired by the code from here: http://bl.ocks.org/mbostock/3943967.
I have learned more about coding and I have created a more efficient way to do this here: http://bl.ocks.org/brennanpincardiff/d07d52f10900c14844b5