You can, but for an even, professional look we suggest a professional stylist. They can help avoid accidental skin bleaching, uneven or ‘overkill’ hair, as well as accidental colour changes.
Usually this is achieved by sectioning off the desired hair and colouring it separately, gently fading into the main body of hair along the way.
Bleaching with the right techniques, products and protective measures will leave very little to no permanent damage when it comes to your hair.
Typically, you’ll need a good shampoo and conditioner that helps replenish moisture levels and add reparative strengthen.
Purpose-based shampoo can help to some degree, but it’s no match for a hair toner, especially if you want to switch to a blonde look. Purple will, at the most, give you a yellow/gold colour.
With naturally dark hair, it can take 2-3 sessions to get the desired effect. If hair product has already been added, 3-5+ is expected, especially if the colouration is permanent.
This depends on whether you’re touching up existing hair or looking for a temporary solution. A simple hair spray can work for short periods at the roots, but for permanence that goes to the roots, a stronger toner and session is needed.