Will the neutral henna change my hair colour, especially on highlights, balayage, or fashion shades?

The henna in this formula is Cassia italica, often called "neutral henna." Unlike Lawsonia inermis (red henna), it contains no lawsone dye molecule, so it does not stain keratin or alter hair colour. Its role is purely film-forming: it creates a thin, transparent layer that reflects light, giving a glossy finish without shifting tone. This makes it safe for highlighted, balayage, pastel, or fashion-coloured hair where any pigment deposit would be visible. The product description explicitly states its role is "not to change the shade, but to make the hair fibre look smoother, softer and more polished." If you've had issues with "colour-depositing" conditioners dulling your highlights or turning blonde hair greenish, this avoids that risk entirely. The only caveat: extremely porous, bleached ends can sometimes grab trace botanical tannins, but Cassia italica is widely used precisely because this effect is negligible compared to red henna. If you're uncertain, test on a hidden strand first.