A colourblind member of our team

Question

My team relies a lot on colour within our code to outline features that need to be worked on (we colour lines of code that need attention). We have a close friend who is colourblind and wants to join our team. What can we do to highlight what needs work without using colour? We have about 25 people on the team that are all accustomed to the line colouring system and we have found it to be most efficient.