Hey guys, my mate was trying to make a solution of ph-10 with 110grams of lye, and 750ml's water (tap water, but boiled and let cool twice).. added it 20g at a time, every 10mins. but it has turned this yellow/orange/amber color?

there was nothing in the jug i used, so could it be some sort of oxidation?
swim was mixing it together in a plastic measuring jug, but it hasn't changed color like this before, any idea's??

What kind of plastic?

If you add more does it get darker?

just the milk/cordial 2l plastic jugs & yes, it was a real slight off-coloration after i added the first 20g of lye, and has turned to a deep, medium see-through, amber/orange solution.. just can't figure out for the life of me what it could be..i stired it with a stainless-steel knife. but doubt that would of done anything..all clean matirials

i though maybe something fly in the mixture, but shurly it would be dead and still in there (the mix is clear) so do you think maybe it could be some partical in the air?