Laundry questions.
Are you sorting lights from darks? Dye transfer happens very easily.
Are you using the "Heavy Duty" cycle?
Are you overloading the machine? Overloaded machines have poor circulation in the tub, and poor circulation = poor cleaning.
Are you using too little detergent? Especially if you have hard water, using too little detergent is another possible factor in poor cleaning. The detergent manufacturers want you to be generous, but using a lot less than suggested is not a good idea.
Have you set the "extra spin" setting, if available on the machine?
We want to help.
Lawrence/Maytagbear