TWW hair lightening and highlights

Beta on Friday after expensive

<a href="https://glowing.com/glow-fertility-program">IVF</a>

... I've over an inch of nearly all grey on top and work people are noticing. Hairdresser suggested a California shampoo to bring black tips to a browner tone and them highlights to as light as possible scattered through to blend the grey. I can then grow out (grey since my teens) and keep cutting. Is this safe during TWW. I will ask clinic and I will tell hairdresser (forgot) but I'd love opinions... Thanks !!!