The US image is not very well labeled, only telling you that the imaging plane is TRV or transverse. It is a view of the central part of the liver, with use of Doppler to show flow direction. The scale to the right of the US image indicates which direction is RED (toward the transducer) and which is BLUE (away from the transducer). Is this US normal?

Color Doppler US portal vein, with CT comparison