If there is a relative motion between a source of light and an observer, a change of colour of the light appears in the eyes of the observer. What is the name of this phenomenon ?

If there is a relative motion between a source of light and an observe

1.	If there is a relative motion between a source of light and an observer, a change of colour of the light appears in the eyes of the observer. What is the name of this phenomenon ?
Answer» SOLUTION :N/A