Today I realised - because of someone else's promotion - that having an unnatural hair colour where I work isn't necessarily the professional showstopper I thought it was.

But rather than jump in the deep end straight off, I figured it would be wise to dip my toe in and check that the water is, indeed, warm. Any suggestions? For context, I have long, poker straight (whatever I do with it), fairly dark ash brown hair.

I was thinking of maybe dark green under my natural colour. Sort of like this:

But less striking because of the colours and almost certainly less well executed.