Maybe someone else knows of a way to do this, but from my limited experience, trying to lighten hair almost always comes with a consequence, worse depending on how much color you want lifted. Tends to damage the hair cuticle and make the hair more porous and dry. That said:

Some use lemon juice or honey (over time), for a subtle lift in color. Color Oops is used by some. The claim is that it's gentle, but I don't know too much about it. It does include citric acid, which could be harsh, but it's one of the last ingredients so I'm not sure.

Ringlet Fandango! ... Where curly ideas roam free

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