When choosing a shade, you should always consider your natural hair colour or your previous hair colour. Define the existing difference between your current colour and the one you wish to achieve.
Choose a shade close to your colour: up to 2 shades lighter or darker than your hair colour.
If you are a darker or olive skin tone, try the warm brown shades of Kolora. The colder shades are more suited to a cold or pink skin tone.
If you hesitate between two shades, choose the lighter one or make a hair strand test. If you like the result, proceed with entire hair colouring.
It is difficult to lighten an already dyed hair, so if this is the case with you, choose a darker shade or use a permanent hair bleach.