stained vinyl flooring

[Gatekeeper]

we've had vinyl flooring down in our bathroom for just over a year and I noticed yesterday in the bright sunshine that areas of high traffic round the bog, sink and bath are looking stained despite regular cleaning. Have tried all varying permutaions of cleaners both man-made and 'natural' home made but nothing helps. Floor is a small grey/silver mosaic pattern with an anti slip finish

Place we bought it from wouldn't help as it was fitted more than a year ago nor could they offer any solution !
Thanks for that Frank's Flooring Store

[Gatekeeper]

I meant to ask

Does anyone have any advice about removing ground in muck and stains?