they use this thin called xylem
yes you can cause its just a food coloring
No.
Jist the littkest drop or your mouth will get stained
I doubt it. But it sounds like something you could easily conduct an experiment to verify.
photosynthesis
Only if yo drink it without anything with it.
your tongue turns black
No, flowers absorb water through their stems to nourish themselves, but they do not consume food coloring. Adding food coloring to flower water can change the color of the petals as the flower absorbs the colored water through its stems.
Unless the food coloring has some active ingredient, it will not affect the salt water chemically. In the environment, adding excessive food coloring to water may reduce the amount of light available to plants living in the water. Otherwise the coloring itself is innocuous.
Of Course not.....if you don't drink water a lot though it will become a darker yellow,
Food coloring is any substance, liquid or powder, that is added to food or to a drink to change its color. Food coloring is used both in commercial food production and in domestic cooking. The FDA's permitted colors are classified as subject to certification or exempt from certification, both of which are subject to rigorous safety standards prior to their approval and listing for use in foods.
Chlorophyll