I can answer from experience with my stones. One goes from purple to green as the day progresses, then to fuchsia in some kinds of light, such as fluorescent lighting, plus so many other lovely hues in-between: pale blue, purplish-blue, dark blue, smoky and a dark grey, a bright emerald green.
The other stone changes from deep purple to deep aquamarine to intense fuchsia. While not showing as many different shadings of colors, this stone is a beauty because of the deepness of the colors.
Alexandrites show a different range of colors depending on the stone, its chemical properties and how it's been cut, so it's important to find out what actual colors your stone will display. Some stones will show yellowish or brownish hues. Many buyers seek stones that turn a deep ruby red. Much depends on buyer preferences for color.