What should I do with my male and female colleagues after my female colleague turned against me and accused me of stirring up trouble between them, this after she revealed to me my male colleague's transgressions with her, and then they started talking to each other again?

What you have mentioned contains many errors, because your relationship with your female colleague has exceeded the limit permitted by Sharia. The principle is that a relationship with a non-mahram woman is not permissible due to the corruption that results from it, as stated in the Hadith: "I have not left behind me any فتنة (trial/temptation) more harmful to men than women." If seclusion with her and the sharing of secrets are added, that is another sin, due to the saying of the Prophet, peace and blessings be upon him: "No man is alone with a woman unless there is a mahram with her." If the woman was married, and the seclusion with her involved something that suggested seeking divorce, then these are accumulated sins. What happened with the woman turning against you might be a punishment from Allah due to your sins. Therefore, hasten to repent and invite your colleague to do the same, and cut off your ties with her.