copper on ps5 board changing color from flux?

[kb59kb]

Hello all - I was working on replacing the HDMI port on a PS5. After I removed the port and cleaned up the area, I noticed the copper appears discolored compared to the rest of the copper where the flux did not touch. The flux I was using is Chip Quik SMD291. I have attached an image. Does anybody know what causes this?

Thank you!
KB

[harp]

Re: copper on ps5 board changing color from flux?

It is color of copper (pink). Looks like flux somehow etching gold plated finish...
So, it is very agresive flux or
very good deoxidation flux or
it is not at all gold on top layer
or it is thin and pourly applied on surface just to look like gold.