numbers – How to color code individual data points in line chart

This is a question about using charts in Numbers and color coding individual data points in a series.

I have two series of data (blood pressure readings) that I plot in a chart. The series may contain multiple readings made at different times on a day, or there may be a single reading.

Is there a way to color code the data points in each series to indicate which part of the day the reading was taken? e.g. 6am-10am = purple, 10am-2pm = orange, 2pm-6pm = blue, etc.

The reason I want to do this is to distinguish between readings taken before and after taking medication.

Here's the chart