Color Doppler is used to provide Doppler shift information within a large region of the image.
When set up properly color Doppler can quickly be used to assess for:
presence or absence of flow
direction of flow
some limited evaluation of the character of flow
Typically color Doppler is the first Doppler modality that is applied. Once color Doppler has determined that there is flow, then pulsed Doppler is used to better determine the details of the flow.
The following videos cover the important aspects of color Doppler: