Assign colors to trend arrows and values for easier interpretability

[mthong]

From @juliemeridian (moved from #87):

Assign colors to changes (the arrow & number) to see at a glance when changes are positive or negative. Green for good, red for bad, and blue for anything that doesn't lend itself to a clear value judgment.

See example here:
https://www.figma.com/file/YINuNVi5uN3iDdYKlkm2XDgP/CodeForSanJose-Economic-Indicators

[mthong]

Here's a screen shot from the link above.

[LaurieSReynolds]

Nice idea.

1. I'd pick shades that didn't match the box grouping colors. (e.g. pick a shade of green that is different from the one that is used for Real Estate.

2. Consider making all the box groups the same color - see Denver's economic dashboard
   http://www.metrodenver.org/research-reports/monthly-economic-indicators/

3. Consider, like Denver to only shade the changes that are good or shade only the good and bad changes and leave the neutral changes grey.