This is a quandary that comes up a lot when talking all things {make up} - customers nod knowingly then carry on buying the shades they LIKE, even if their best-loved brick red-coloured lipstick clashes abysmally with their cool colouring (no-one wants to look like they're an extra in a Burton film).

When you get things right, especially when it comes to base and cover-up, your face will look more radiant, your eyes brighter and your hair colour much more vivid. An understanding of the 'undertone' is what ensures so many firm red carpet fixtures look so luminous (of course, genetics help) - even when their image hasn't been enhanced in post-production. So, how do you tell if you're 'cool' à la Scarlett Johansson or 'warm' like Ms. Kidman? Our tips will help to guarantee you always put your very best face forward.

Not to be confused with skin tone (which is your 'shade' and often changes with the seasons), your undertone is what dictates the hues that suit you best. We've all had times when those around us notice that a colour really makes us look 'alive' - that's a sign that you've alighted on a shade that really complements your colouring.

If you have warm undertones, it means that your skin is predominantly yellow, gold and olive, whereas those with cooler colouring have skin composed of pink, blue or red tones. You can of course be somewhere in-between - in which case, you'd be classed as neutral (and the colour world's your oyster). Still at a loss? Here are three simple ways to work out where you sit...

In natural light, look at the veins on your wrist (try not to do this when you're cold as veins will be constricted so they're less visible). If your veins look blue, you're cool and if they have a greener tint, this is due to your warm undertone affecting their appearance (remember school? blue + yellow = green). If they're neither one thing nor the other, you might be neutral-toned... these next steps will help finalise which camp you're in.

Precious metals are another way of working out your undertone. If silver makes your skin look luminous, you're typically cool - while gold is the go-to for those with warm or golden tones. Neutral? You can get away with both... (ALL the jewels!).

Lean towards strong, jewel-toned hues? Blue-toned ruby reds, royal purples, emerald greens and ultramarines? It's probable you're classically cool-toned. While those who favour warm autumnal tones (mustard yellows, corals, orange, browns and yellow-based greens) are typically 'warm'. If you look good in either (lucky thing) you're almost definitely neutral.

An increasing number of foundation ranges are not only expanding their shade range to ensure they now cater to the spectrum of skin tones, but also come in an array of undertones so it's now (theoretically) even easier to find your perfect match... providing you feel confident about whether you're cool ('P'), warm (often 'Y' for yellow or 'G' for gold) or neutral ('N').

Brands such as {Cover FX}, {The Ordinary}, {BECCA} and Huda's eagerly-awaited {#FauxFilter Foundation} all boast an impressive range of shades and tones from ultra-pale with rosy hues to beautifully deep with rich, red undertones to 'lift' complexions prone to ashiness.