Try to use an expensive detergent, it washes well not only jeans, but also protects them from the penetration of dirt deep into the fibers. Wash at a temperature of 40-50 degrees.
If the jeans turned yellow, add two tablespoons of hydrogen peroxide during the wash to the powder. The peroxide can be added to the main compartment for powder in the washing machine, it will not damage rubber elements.
The use of baking soda for every wash lightly bleached jeans. Soda softens the water and powder it washes pollution. Soda is necessary to take 1 h spoon per liter of water, while the drum washing machine can add 1-3 tablespoons of baking soda.
If all else fails – soak the jeans with lemon juice. You can use citric acid. The proportion of lemon juice 1 tbsp per gallon of water. Citric acid you need to take at the rate of 1 h per liter of water.
Use with each wash, oxygen bleach and after a few washings you will notice the result.