Just putting this here for when you next look at things. I’ve posted about this in the support forum in the past but your support guy said it works. At the time I didn’t realise it was due to me using a Global Colour.
I can replicate this on any new build so definitely a problem.
If you set the ajax add to cart colours using a Global colour this does not reflect in the front-end when adding to cart. The colour stays with the default green,
If you don’t use a Global colour then it works as expected.