Think you're having trouble staying on top of this season's fashion fads? Well, just try keeping up with the hottest hair colour trends.

Scarlett Johansson recently turned to the bottle for the fourth time this year for a dramatic colour change, ditching her trademark blonde for autumnal brunette.

And the actress isn't alone in using hair colour to make a dramatic statement. Forget the stylist, the colourist is every celebrity's secret weapon...

In August, Cheryl Cole shocked onlookers with a deep plum shade for a photoshoot and trend-setting Peaches Geldof followed suit. Fast-forward a couple of months and Cheryl's back to brunette and Peaches is dark blonde.

Now the skies have turned grey for winter, women are craving colour. The hair colour industry is worth £153 million in the UK alone and 64% of women regularly colour or highlight their locks.

"Colour is one of the easiest ways of transforming your look," says hairdresser Andrew Barton.

Whether you want to maintain your colour or work a stop-and-stare shade, make sure you have hair that's to 'dye' for this winter.

The hair industry's top experts are on hand to answer your most commonly asked colour questions.

Shady lady

It's easy to be flummoxed by colour charts and types of dye jobs at your fingertips. Ensure you take your skin tone, budget and commitment levels into account before you colour.

- How can I choose a flattering colour?

"It's really all about the skin tone and eye colour," Andrew Barton explains. "The more dramatic the hair colour change is from your natural hair colour, the more make-up you'll need to wear. Girls with darker complexions tend to suit shades that are warmer like reds, rich browns and warm blondes, where paler skins suit pastel shades, icy blondes and pale browns."

- I'm a first-timer to colour, how will I know if it suits me?

"If you are going darker or changing the tone completely, I would recommend using semi-permanent colour, certainly in the first instance, as this will fade naturally," suggests 10 Years Younger colourist Lisa Shepherd. "From there you can assess whether the shade suits you and if it is something you can wear permanently."

Permanent colour conundrums

Should you leave your hair in the hands of the experts or take the plunge and save cash with DIY colour? Whatever you decide, ensure you wait 48 hours after carrying out a skin allergy test and check out www.becoloursafe.com

-  I can't stand the smell and sting of ammonia in the salon, is there an effective alternative?

"L'Oreal Professional's Inoa ( www.inoa.co.uk ) is the new odourless and ammonia-free permanent hair colour," explains Julie McManus, L'Oreal senior scientific advisor. "Hair colourants do traditionally damage the hair but with Inoa, which has been developed with a very conditioning formulation, the condition of the hair is actually protected."

-  How can I tackle root re-growth?

"When colouring at home, if you apply colour all over the hair each time you dye, it can become unnecessarily dry and damaged," warns stylist Sean Hanna. "By applying the colour product only at the roots or the area where it is needed, over-processing can be avoided."

-  How often should I colour my hair?

"Colour your hair every four to six weeks to help prevent colour banding within the hair," advises celebrity colourist Mark Ramos.

Fade-free tresses

After spending hours in the salon chair changing your colour, holding on to that glossy mane should be a pampering priority.

-  Do I need specific shampoo and conditioners for post-coloured hair?

"Regular shampoo and conditioner can or may contain sulphates - these detergents will clean the hair but may strip and remove colour that you have had lovingly applied resulting in colour fade," warns Sarah Brookes, Tigi international creative director. "Ensure that you are using shampoo and conditioner that specifies it is colour safe, sulphate-free shampoo to help prolong your colour."

-  How can I avoid fade?

"With freshly-coloured hair, don't wash it too frequently - water is the main cause for fading," advises Dr Frauke Neuser, Clairol scientist. "Always protect hair colour against the sun. There are various heat protection products available but the best of all is a hat."