<prompt> The intensity of colour in Doppler is determined by:Direction flowVelocity of flowStrength of returning echoNone of the above  <response>: In a Colour Doppler: Colours are used to represent direction of flow towards away from the transducer; usually blue is towards red is away from transducer Shades intensity of colour represent v elocity of flow; the paler shades representing higher velocity Power Doppler: Is good for showing areas of flowing blood, paicularly when it is moving slowly or in small vessels; but at the expense of losing directional velocity information. 