The Mistery of the Lights

Guys, check it out! The mistery grows! If you take a second look at the picture, you'll see that the three set of lights are close to some bush and there are two types of lights, three colored lights and two white lights. Maybe the lights are indicating wich bush hasn't been harvested for a while? Or they mark the bushes that have the highest chance to drop steedgrass? Who knows? I haven't harvested any of the lighted bushes yet, but as soon as I do it, I'll report what they dropped.