They are symbolizing the supply and demand zones so they vary according to body length of the candle. I want bot to react those colors and take entries

Hello everyone,
Im working on an expert advisor which should sell when at supply zones and buy at demand zones. I have a custom indicator and yet i can't still do that simple expert advisor. Everything is so complicated for me. I really appreciate for some help and i know it will be easy but i cannot do it still.

Thanks in adance