Brassy tones are usually a problem for tube blondes, but it can happen to dyed brunette hair, too, especially cool or ashy brown. Golden and ash highlights can turn to orange in just a few washes, as the original layer of dye is stripped away.
You don't have to run back to your hairdresser when you see the first hint of brass in your hair! There are plenty of DIY ways to restore your original colour or at least postpone your next dye job a bit longer.
1. Colour-correcting shampoo
Colour-correcting shampoos are shampoos that have trace amounts of purple or blue dyes that cancel out the brassy tones in your hair. They work slowly and gently, removing a bit of brass with each wash.
If your brassy tones are more coppery/orange, then choose a blue colour-correcting shampoo. If your tones are yellow, choose a purple one. Why purple or blue? Look at a colour wheel: purple and blue are the opposites of yellow and orange, respectively, and they cancel each other out.
In doubt, use a generic colour-correcting shampoo that has a bit of both blue and purple; it's usually labelled as "shampoo for brown hair".
2. DIY Colour-correcting shampoo
If your scalp is sensitive to shampoo changes, you can add 2-3 drops of food coloring to what you already have. Choose green food coloring if your brassy tones run more red, or 2 drops green + 1 drop blue if your hair pulls more orange.
Wash and rinse as usual, or leave the shampoo in your hair for a couple of minutes for a stronger effect.
3. DIY Colour-correcting toner
If you need something stronger, make a colour-correcting toner by adding 1/8 Tbs of food colouring (blue or blue + green as in point 2) to 2 ½ cups of white vinegar. Pour this over your hair and gently massage it in after shampooing as you usual, then rinse with cold water. If your hair needs a pick-me-up, use apple cider vinegar to make it more glossy and soft.
This is the newest and most delicious method of hair dying. Some hair stylists use it to dye blonde hair a darker colour, but you can use it to neutralize the tones in brown hair, too.
Slathering your hair with Nutella and leaving it results in a slight caramel or mocha tint, depending on how long you leave the Nutella on top – the longer, the darker. The results are temporary, and your brassy tones will be gone for 3-4 weeks until they start resurfacing again.