What does red mean on an abdominal ultrasound? The red and blue colours on the screen during your ultrasound in London indicate the direction of blood flow. You can read more about Doppler ultrasound Imaging. You Might Also Like What happens after the examination? 25/01/2022 Will abdominal ultrasound hurt? 25/01/2022 Can you see cirrhosis on an ultrasound? 25/01/2022