Hi Kevin, thanks for an interesting post. You did a nice job of explaining the categories. I had to look up the acronym associated with your orange color: Address Resolution Protocol.
Your plot is in time order, but probably not time scaled. If it were time scaled, I expect there would be lots of white, assuming white means network inactivity and/or any activity not associated with Sense. The amount of white might wash out the colors, which is probably why you used time order in the first place.
If you had used time scale, I expect that the light blue would occur at predictable spacing, since Sense has to poll the smart plugs on a fixed schedule. I think the schedule is every 2 seconds for most people, although users with more than 20 smart plugs may have longer intervals. Since there are broad swaths of light blue between each swath of light green in your time ordered plot, that mean that Sense polls Philips/Hue even less frequently. This rings a bell with my observations of that integration: