1. Pick the right formula. Permanent colour lasts longer, while semi-permanents are ideal for "first-time colourists, covering a few greys, or for those who regularly change their colour", explains Tapp.
2. Find your match. "Whether you're going lighter or darker, stay within two shades of your natural colour to ensure your new hue flatters your skin tone and eyes," suggests Tapp.
3. Take a test. To keep sensitive scalps happy, do a patch test at least 48 hours prior to colour application to ensure there's no itching, burning or discomfort.
4. Follow instructions. "Enclosed information explains how to apply colour for the first-time users," advises Tapp. "For frequent reapplication, it helps avoid colour build-up on the ends."
5. Toss the rest. Mixed formula loses its potency over time (this is why the components are packaged separately).
6. Don't over wash your hair. Your natural oils help protect the scalp when using permanent or semi-permanent colour; dirty hair, however, can prevent the dye from penetrating.
7. Take another test. Mix the colourant with the developer and apply to a strand of hair (root to tip). Leave for the total recommended time, then check the result.
8. Protect yourself. Smear some Vaseline around the hairline and on ears to avoid staining (otherwise, use a gentle exfoliant or cleanser to wash off stains, or try 1000 Hour Hair Color Stain Remover, $3.99).
9. Skip the brows. Never apply home hair colourant on your eyebrows - only use a specially formulated brow product for the delicate eye area.
10. Use the included conditioner. "This eliminates excess colourant and re-establishes your hair's natural pH balance by closing the cuticle," explains Tapp.
Before you try this at home...
-More than three levels lighter or darker than your current colour: "I wouldn't recommend taking black or dark brown hair to blonde at home," warns Claire Tapp, national education manager at L'Oreal Paris.
-Colour correcting: you've made a mistake. Now seek professional help (but if you just want your natural colour back, try Colourless Max Effect Hair Colour Remover, $26.95).
-A tint-back: going back from light to dark requires extra pigments that have been removed during the lightening process - leave it to your colourist, says Tapp.
Those numbers mean something!
The numbers on the box refer to base and reflect tones. "The number before the decimal point is the base shade pigment and gives the depth and grey coverage, and numbers after the point are colour tones," explains Tapp. If you have lots of greys you'll get better coverage using a base shade, like an 8, or a shade with just one reflect, such as an 8.3.
Expect to see warmer browns "with rich golden, biscuit hues that have a softness to them", says Danielle Solier, a L'Oreal Professionnel coloursit at Victoria's Xiang Hair.
Pink and pastels are still big, but now you'll see pastel versions of magenta and emerald. "For the more daring, try neon accents, like grey roots with neon-yellow ends," suggests Solier.
Platinum blondes aren't going anywhere this season. "You want crisp and clean colour, so invest in blue or purple-based shampoos to keep brassiness in check," advises Solier.
"It's a practical look that's part of the '90s trends we've been seeing," explains Solier. Stick to one-inch regrowth or shadow tone to keep it current.
It's all about the redhead this season. "Spring will start with the warmer shades like strawberry red, and then move to cool reds like true ruby and rich wine reds," explains Solier.
"Blorange is going to be the big colour," predicts Solier. "More peachy than rose gold, you can go vibrant and really stand out, or work with more wearable pastel peachy shades."