As an interesting point when one says he sees a rainbow it is loshan horah. Why, he wants us to do teshuva. Maybe, the Klei Yokor explains it says בימות רבי שמעון בר יוחאי לא נראתה הקשת at the time of Rabbi Shimon bar Yachai the rainbow was not seen, should have said there was no rainbow?
He says that that they relied on the gadol to protect them and did not look to see if there was a rainbow. According to this it is lashon horah because we don’t trust the gadol that he protects us or we don’t recognize the gedolim.
