If white shirts are coming out of the wash looking grey, or if coloured laundry is fading too quickly the first thing you need to look at is the type of detergent you are using.
Different washing machine detergents work in different ways. Some contain bleaching agents, which helps keep whites white – but that also fades colours. Other detergent claims to be friendly to coloureds – but it achieves this by not using bleaching agents so whites may not be kept as white.
So this logically means that if you have laundry that needs to be kept nice and white you should use detergent with bleaching agents in. But if you have coloured clothes that you want to keep from fading as long as possible, you need to use a colour friendly detergent. In other words you need to buy both types.
Apart from using good quality washing machine detergents you also need to use the correct amount. Using less can cause a build up of grease and grime in the washing machine as well as poorer wash results.
Not using enough detergent can also cause limescale problems. Washing machine detergent contains ingredients that protect the washing machine (particularly the heating element) against limescale. Not using the proper amount may appear to save money in the short term but may well end up costing much more.
Many people are happy with the wash results they get when using lower doses of detergent but if that’s you, check underneath and behind the door seal to make sure your washer isn’t getting slowly choked up with grease, limescale or slime. (Washing machine smells – causes of grease, slime and black mould inside washing machines)