What do the different colored lightsabres in Star Wars mean?

Answer 1

some of the loose patterns of note are that blue sabres indicate a Jedi more intent on combat that the force, while green is the opposite and purple, being a combination of blue and red indicates that a Jedi has focused his education on combat but has gone and come back from the dark side to learn the special elements of Sith combat. Also, it seems that a higher percentage of certain stations of Jedi use certain colors, like blue with Jedi Guardians, Green with Consulars, Yellow with sentinels.