“Make your nail polish last longer by applying your favorite color and then, once dry, wiping your nails with a cotton ball soaked in white vinegar”. I am not sure, how this work but I might try it.
“If you have coarse hair, your strands are likely to be more color resistant [if you’ve got grays, you might have noticed this]. But that doesn’t mean you can’t increases your chance of a good outcome.
If your hair is a little wiry - the night before, wash with a clarifying shampoo or rinse with apple cider vinegar to eliminate product buildup, which can keep color from penetrating hair shafts.
If your hair is coarser - do a strand test using the recommended amount of dyeing time. If the color hasn’t taken, leave dye on 10 minutes longer than instructed but thats it.
If your hair is super coarse - blast it with a blow dryer while the dye sinks in. This will open up the cuticle, letting the color penetrate better. Next, cover your head with a shower cap to trap the heat, remove it 10 minutes prior to rinsing, then rinse with cool water. Doing so helps seal the cuticle and lock in the color.”