Clean out the Green
Measure out a cup of tomato sauce if your color left your hair an icky shade of green. You're not trying to turn your hair into an Italian pasta dish, so stick to plain tomato puree and put down the chunky tomato basil.
Pour the sauce over your damp locks in the shower. The red tones in the tomato sauce balance out the green, and the acidity helps the sauce penetrate your hair.
Give your hair a good scrub with your fingers. Really get the sauce into your hair from the roots to the very ends, because blotchy green hair is no better than all-over green hair. Let the sauce sit for five minutes.
Rinse out the red. If the smell of a bistro is making you nauseous, wash and rinse again with a clarifying shampoo.
Cover-up left-over green with a slightly red-tinted dye. Stick to a red-toned color that is as close to your natural shade as possible to avoid yet another disaster. Follow the manufacturer instructions so you don't end up in an endless cycle of fixing dye jobs.
Tone Down Brass
Go blue with shampoo if your blond locks turned brassy orange. Blue shampoos are specially tinted to contrast with orange or yellow hair. Wash and rinse your brassy hair with a blue or violet shampoo for an immediate reduction in the brass factor.
Tone down brassiness with a toner. Toners are semi-permanent hair dyes that work by laying down pigments instead of stripping color. Go for ash blond or light golden blond.
Invest in brightening styling products. Blue shampoo is just one weapon in the anti-brass arsenal, and brightening shine spray and serums use the same blue-based color theory to tone down brass during your regular styling routine.
Return From the Dark Side
Mix up a color-fading cocktail to lighten up too-dark dye. Stir a 1 oz. dollop of your regular shampoo in a 2 oz. splash of peroxide. Massage the mix through your hair and scalp, and wrap up your hair in a towel or plastic wrap and check the color after five minutes. Rinse out the mixture, and if it's still too dark, repeat.
Swap out your regular shampoo for a volumizing shampoo. Volumizing shampoos work by roughing up your hair's cuticle, which means color can be more readily rinsed out with hot water.
Go with a natural hair lightener like lime or lemon juice. Mix up 1/4 cup of lemon juice with 1 cup of water in a spray bottle and spritz your strands. Let the juice sit for 10 minutes and rinse it all out. Keep it up once a day for up to week until your light locks have returned.
The best way to fix a hair color disaster is to never have one. Do a test strip before you dye your whole head, and follow the manufacturer instructions for applications and rinsing.
If your hair is beyond home repair, call a stylist and get into the salon pronto.
Don't over-process your hair with repeat dye jobs. Hair dyes use harsh chemicals that can strip hair and dry your hair out in no time.