I use traffic signal colors of red, yellow, and green to compare two traffic risk behaviors:
comparing Rarely or never wore a seat belt with Rode with a driver who had been drinking alcohoI.
To dramatize color effects, I colored the spaces around the line
based on the ranges of 95% confidence interval.
With the colored spaces, I want to make it easy for the viewer to see the color changes
of two behaviors, from red to yellow and from yellow to green,
which mean two risky behaviors are both decreasing.