It is not used to track anything. If you have a transaction number, that is just a receipt from the post office or store where the package was mailed. USPS does scan pieces at its distribution centers, but that doesn't mean that individual pieces can be tracked by those transaction numbers.
The hexadecimal color code #419547 is a shade of green. In the RGB color model #419547 is comprised of 25.49% red, 58.43% green and 27.84% blue. This color has an approximate wavelength of 547.6 nm.
The Anime producers deceided to make the scarf red in colour as a reference to the Red String of Fate that connects people that are destined to meet (or destined to being lovers).
A pigment within the chloroplasts of a plant cell is responsible for the green color. … Although the bulk of the plant cell is colorless, the green appearance of plants exists because of a pigment found in the chloroplast.