I'm afraid the answer is No. I don't think it's possible or recommended to configure two sets of color ranges in one radial gauge and dynamically switch between them based on the value. Even you could do so, it would not be good, consistent visualization practice and may lead to confusion.
Let me answer the easier question first, you cannot use two colors for a value 🙂
Now, for the second question. It is possible to configure dynamic threshold in radial gauge, but I am not sure I understand what's in your csv and how that relates to thresholds. Can you share sample data from your csv?