NaillyThe same bottle of polish can look luminous on one hand and exhausted on another, and the difference is not luck — it is undertone. Learning yours takes two minutes and permanently upgrades every colour decision from polish to jewellery. Here is the working guide: how to find your undertone, what genuinely flatters each, and the shades that flatter everyone regardless.
Find your undertone in two minutes
The vein check: look at your inner wrist in daylight. Veins reading blue or purple suggest a cool undertone; green suggests warm; a mix or hard-to-say usually means neutral.
The jewellery check: if silver visibly brightens your skin more than gold, you lean cool; if gold warms you up, you lean warm; if both work, neutral (congratulations).
The white test: hold stark white fabric to your face — if you look fresher against cream than pure white, you lean warm.
Note that undertone is independent of skin depth: deep skin can be cool, fair skin can be warm. Both dimensions matter for polish — undertone picks the family, depth tunes the intensity.
Cool undertones
Your friends are blue-based colours: cherry and raspberry reds, fuchsia and cool pinks, plum and berry, true navy, and the greys from dove to charcoal. Your nudes are the pink-beige family — a warm caramel nude will read orange on you. Silver chrome over milky white is practically bespoke. Approach with care: orange-coral, olive, and anything golden-yellow.
Warm undertones
You get the sunset shelf: tomato and poppy reds, coral and peach, terracotta, butter yellow, olive and warm browns from caramel to chocolate. Your nudes lean golden-beige; a pink-based nude can turn you ashy. Gold chrome and champagne glazes were made for you. Approach with care: icy blue-pinks and stark blue-whites.
Neutral undertones
Most colours behave, which moves the decision to depth and vibe: soft-muted shades (sage, dusty rose, greige) read effortlessly harmonious; ultra-saturated brights read bold. You are also the undertone that wears unusual colours — grey-green, mauve-brown, blue-grey — with the least risk.
Deep, medium, fair: tuning intensity
On deep skin, saturated and sheer-dark colours sing — cobalt, emerald, cherry cola jelly, chocolate glaze — while chalky pastels can sit flat; when you want pastel, choose ones with a sheer or jelly body. On fair skin, very pale polish can vanish — a micro French or a slightly deeper pastel keeps definition. Medium skin has the widest safe zone and the fewest rules.
The universal flatterers
Five that work on effectively everyone: milky white (borrows your own tone through the sheerness), glazed donut (self-adjusting by design), cherry-cola sheers, true deep red in the right temperature (pick your red family), and classic French over a base matched to your undertone's nude.
Test on your hand, not a stranger's
Every polish photo you have ever saved was colour-graded on someone else's skin. The Nailly design studio lets you run any colour across a full designed set and compare families side by side — and the shade you settle on reaches your artist pinned to a real polish name, not a screenshot filtered beyond recognition. Undertone finds the family; seeing it settles the shade.