What does the omen in the paragraph of the weather tree mean?

If the leaves change from bright red to light red on rainy days, and then gradually turn back to green, it indicates that the weather will get better.

The largest tree of this kind is more than ten meters high, and its chest is as thick as a bucket. The leaves are about two fingers wide and two inches long. It's usually green. Every time it turns sunny and rainy, the leaves will turn red; Light rain is reddish or half-leaf red; Heavy rain turns red or all leaves turn red; After a day or two of rain, it turned green again. Before the long rain clears up, there are also omens: the leaves turn pale red or semi-red, symbolizing that the rainy day is about to pass and the sunny day is coming; When the leaves turn red or all of them turn red, it tells people that a dry elephant is coming. A day or two after it clears up, it will turn green again. This kind of tree can forecast the weather, and local people have the habit of looking at the color of the tree when arranging farm work or going out for business.