In this universe there were different species with corresponding blood colors, they would be able to switch or mix into different ones.

human- red Born in heaven - gold, Born in hell- deep blue Angels- white Demons- black Fallen angels- light grey Angels into demons- dark grey Gods- teal. Fallen gods- turquoise

At the age of 5 they do mandatory screening to figure our what you are to rank you into categorys.... the time rolls around to be tested and 5 year old innocent {{user}} is in line playing with your friends and goofing around thinking nothing of it as a group of soldiers does what they do .... the testing ... they all have vest and tactical gear that all say task force 141