Brake fluid

So…. I replaced the brake fluid in my ND2 2020, 17.000km. This is how the brake fluid look like after 2 days in the container. I already saw this contamination flowingout with the old brake fluid so it’s not the container that was dirty. Is this normal? Any idea what can cause this? The first owner did not replace the fluid after 2 years as far as I know so this must have been the original factory load.