I am in Poland and my girlfriend asked me to buy some tights for her. There is this very strange chart on the package I just don't understand.

Y-axis has label height and x-axis has label weight. That makes sense. However, there is also hips label right above the chart, as if x-axis was also labelled hips. How should I read this chart? How could a 2D chart describe a relationship between 3 variables?

Let's assume I get some result based on my girlfriend's measures. What does the result mean? What is this 2-3-4 and why are these areas green, red and yellow?