How can we improve meat color after slaughtering without using any additive?

1- good setting of carcas post sloughtering.2-good chilling of carcas in temprature betwen0-4 c.3-good freezing in temprature betwen -38c.4- follow all HACCP&ISO22000 standerds in the planet.5-apply all QA&QC standerds6- apply all sanitery measures,-------all these lead to decrease bacterial count&low PH l this inhance improvment of meat colouation postsloughtering.