How long should I leave toner in? Is there a universally accepted timeframe that one should adhere to when utilizing toner, or does this vary significantly based on individual hair types and the specific formulation of the product? Given the plethora of toners available on the market, each boasting distinct active ingredients, is it prudent to follow the recommendations provided by the manufacturer, or should personal experimentation guide our decisions? Additionally, could the desired outcome—whether aiming for a subtle hue adjustment or a more drastic color correction—influence the optimal duration for which toner should remain in contact with the hair? Are there any particular signs that indicate when it is advantageous to rinse the toner, thus ensuring both the vitality of the hair and the achievement of the intended aesthetic? Ultimately, how does one strike a balance between caution and creativity when applying toner, given its potent capacity for transformation?