Red: The red parts will stay the same
The blue parts will turn black - there is no red in blue
The white parts will turn red - there is red in white
Blue: The blue parts will stay the same
The red parts will turn black - there is no blue in red
The white parts will turn blue - there is blue in white
Answer:
The star must be moving "closer" to the earth because the wave fronts that are being emitted are shifted toward the blue end of the spectrum (they are closer together)
