How Do I Prevent Homemade Pickled Onions Going Dark Brown?

[andypalmer67]

When pickling onions, after a while in the vinegar they go a dark brown colour. How can I prevent this?
Also, what is the best vinegar to use? I am in the UK.
Thanks in advance :-)

[barry1010]

Use distilled vinegar to keep them white, malt for brown

[barry1010]

This is the sort of distilled vinegar you should use but I much prefer the flavour from using brown malt vinegar. Personal choice. https://www.sarsons.co.uk/range/distilled-malt-vinegar

[ToraToraTora]

you don't, brown is good!

[andypalmer67]

Thank-You all, MUCH appreciated ! :-)