[JOJO91343]

You may try Lactic Acid Instead of Citric Acid.  It may require you to add a lot more Lactic Acid than what you should add from Citric acid.  If you use Citric Acid in the adjustment, it may decrease viscosity significantly either shortly after the adjustment or on the long run.  When you adjust with citric Acid, you may get pH in the spec range, but, by the time you test for finished product to release the batch, you may get viscosity on the minimum of the Spec. Range which could be released, but, by the time, the product stays on the shelf in the Retail Store and Customers buy it, it may become very watery.

[JOJO91343]

You may try to adjust pH in the range:  5.5 - 6.5 in a Lab Batch, hopefully, the green color will stay for a while