Picking a shade is the easy half. The half that decides whether you like it in three months is lift, tone drift, root schedule and what your hair can physically take. This advisor covers both, and will tell you when the colour you want needs a professional rather than a box.
Whether gold or silver jewellery looks better against your skin, how your veins read, and how you react to sun are quick proxies for undertone. Cool skin generally holds ash and beige tones cleanly; warm skin turns those muddy and takes gold, copper and caramel instead. Getting this right is why two people can dye their hair the identical colour and only one of them looks well.
Going darker is one appointment. Going lighter is a process, and each level of lift takes something out of the hair that conditioner cannot put back. Two levels is usually safe at home; four is a salon conversation; going blonde from box-dyed black is a multi-session correction and anyone telling you otherwise is selling something.
A shade three levels from your root means a visible line in four weeks. Root smudges, balayage and shadow roots exist to buy months instead of weeks. Deciding how often you are willing to book before you choose the colour saves most of the regret.
How do I know my undertone?
The jewellery test is the fastest: hold gold and silver near your face in daylight and see which makes your skin look clearer rather than sallow.
Will it recommend box dye?
For darker or same-level shades, sometimes. For lightening, grey blending on a heavy grey percentage, or anything on top of existing colour, it will send you to a colourist and explain why.
Can it help with grey coverage?
Yes, including the difference between full coverage and blending, and why a demi-permanent often ages out more gracefully than a permanent.
Is it free?
Yes, no signup required.