I have a top which is cream whereas I suit white much better. Thought it would easily bleach but no, doesn’t seem to make any difference. Not sure what you can suggest really as I’ve tried bleach, but as a long shot, is there anything else I can do to whiten it?
Well it depends on the fabric but I have a cream top (viscose I think) which I unthinkingly put in a hot white wash with a scoop of Vanish a few times. It's a lot nearer white now (which is annoying as I liked it being cream!).