Clear citric water pulls turn dark brew as reduced

[modern]

Any explanation on why an almost clear extract becomes dark after reducing? I think most of the sugars were pulled with PC pulls

So for my caapi yea I do 3-4 PC pulls then reduce everything to 1.5-2L. These pills tend to be a creamy brown for 1-2 and others just a red/brown liquid.
Usually just toss the caapi after this but decided to do some cold acid pulls in the spent bark since under 365nm light it is still very blue with just water soak.
24h citric acid soak leads the the first photo. I did 3 soaks and am reducing and the once clear liquid becomes a very dark color.
The last photo shows the blue of the spent caapi in water soak. Poor photo but shows what I needed

 

[modern]

First 3-4x water pulls with PC vs BLACK 2-3x cold citric water pulls

 

[modern]

it seems that low ph pulls lots of other impurities since when increasing ph to precipitate while still acidic there is a black precipitate that forms around ph 4-5? making the tea brown. The precipitate later redissolves around 6-7ph and cannot be seen again.

Better photo of the caapi vine in citric water after (normal waters pull for tea no acid added).

I'll add photos of the impurities that are pulled with more acid later

 

[modern]

The first photo is the precipitate that forms when still acidic and the second is when it starts to become a more recognizable beige or creamy brown color. Still acidic.