[Userscript] Keisei 形声 Semantic-Phonetic Composition

Dumb question but what do the radical marks on top of the kanji boxes mean? I see 天, 上, 中 and 下radicals with different colors like green, red and orange at the top. Clicking on it also changes the color of these marks. I’ve just installed the script and did not see any details regarding the marks and colors, can someone help me on what these are and how they help with the info?

天 = perfect phonetic match
上 = strong phonetic connection
中 = weak phonetic connection
下 = no phonetic connection

Thanks! But I still have doubts on what that really means. For example, here for 子, 胡 gets a strong phonetic connection despite being pronounced as こ just like the perfect matches. And for 生, the first perfect match is colored yellow while the rest are green. I guess I’m mainly confused about the difference between the four phonetic types and their colors.