The four images shown in sequence here were taken over a span of 6 minutes, 51 seconds.
This was the first sunset observed in color by Curiosity. The images come from the left-eye camera of the rover's Mast Camera (Mastcam). The color has been calibrated and white-balanced to remove camera artifacts. Mastcam sees color very similarly to what human eyes see, although it is actually a little less sensitive to blue than people are.
Images credit: NASA / JPL-Caltech / MSSS