The pepper plant is not a tree but a vine that wraps around other plants. Only the fruits of species belonging to the Piper genus are entitled to be called "pepper."
The botanical family of Piper can be segmented as follows:
The degree of ripeness at harvest and the post-harvest process will give the pepper its final color and flavors.
4 colours of Piper nigrum:
Red pepper, Green pepper, Black pepper, White pepper.