How to get sleeves white again?

This blogger has good tips on that. https://oureverydaylife.com/how-to-whiten-dirty-white-sleeves-12624060.html

If the coat is washable, figure out what is making the sleeves dingy. If it is always at the cuff it may be body oil which should wash away with shampoo. If it is just from rubbing against the surfaces of the world then it should clean up with detergent.

If the coat is not washable it is your dry cleaners problem. When you dry clean white ask them to hold it for an all white load. You may have to wait longer to get it back, but you will stand a better chance of not having it come back a little off white in color.

Hi Bonnie, this may help

our a cup of distilled white vinegar in a clean spray bottle. Pretreat dirty sleeves or any other stains on the shirt by spraying directly on the problem area. Rub the sleeves together to drive the solution into the fabric. Add another half to a full cup of distilled vinegar in with your laundry detergent when you wash the item.

Mix in roughly 1/2 cup of dishwasher detergent with your regular laundry soap to increase whitening power.

Toss a cup of baking soda in with your dingy whites. Sodium bicarbonate's mildly abrasive and absorptive properties are quite effective at scrubbing whites clean -- even removing grease and adhesives.

Add 1/2 cup of lemon juice to your whites when you launder them. Lemon juice also makes an effective pretreatment when you soak the item in lemon juice and hot water for about an hour before washing.Tip

• Spritz armpit areas of white shirts with a detergent and water combination to prevent stains from setting and making them easier to remove in the laundry.
• Dry clothes on a clothesline in the sun to freshen and whiten clothes.
• Always separate whites from colors to avoid dinginess.

If the coat is washable... soak in Oxiclean overnight. That stuff is amazing!