Depends on the risk and how fastidious you are. Colour codes were developed to simplify the process of separating cleaning into zones related to risk. so you had one for toilets, one for kitchens, one for low risk and so on. This meant that in theory you wouldn't make the mistake of using a mop used or high risk cleans such as body fluids in an area where food was prepared or dressings were changed. Personally I use a microfibre flat mop system as normal mops are not the best method for cleaning. When I have finished the toilet area I change the mop pad for a new one for the kitchen and again for each room. That way I don't have to unscrew the mop head every time or carry 5 different types of mop and 5 buckets. Then I wash them out and pop them in the washing machine (don't use fabric conditioner) and use them again.