I've been dyeing my hair at home for a few months now as highlights weren't covering the greys enough and it would be too expensive to have it done at the hairdresser frequently. I have naturally mousey / dark blonde hair with quite a few white hairs noticeable at my hairline and currently using Nice and Easy light ash blonde: the colour is ok but it doesn't cover all the white hairs. Any recommendations? Am I better going lighter or darker to cover the pesky whites?