beautiful 1950s tulle wedding dress, but it's yellowed. Anything I can do?

[TinyDiamond]

I love the dress and it is like it was made for me but the colour is a bit off as it is so old (1952) Is there an easy, cheap, safe way of lightening it. I wondered whether sunlight would help? But as it's meant to be a surprise I'm not sure where I could hang it without anyone seeing it.
Thanks

I am sure I saw someting on those 2 ladies that clean houses ( with funny gloves) re getting yellow net curtains white ....I honestly can't remember as they use pretty basic stuff ...

I would talk to a good dry cleaner if it was me. My wedding dress has gone peach colour on the lace. If I wanted to sell it on, I'd go see my dry cleaner as they are possibly the most knowledgeable people for cleaning etc.