If your wooden floor gets a water (or other) stain, it can spoil the whole look of the place.
There’s no easy way around this – you’ll need to sand the area and apply a wood stain of the same colour over the top.
It can be difficult to judge since different woods take stains in different ways. Any stain you use should be applied in the direction of the grain.
Also, don’t overdo it – much better to apply a little at a time and wait until dry before you think of adding a further coat. Incidentally, it’s worth having a go first with cold black tea.