I am questioning the result of my ecent classroom experiment...please help:I am testing to see if CO2 is released or consumed:

4 tubes with phenol red in all.
1 added elodea plant and placed in bright light
1 nothing added to the phenol red placed in same bright light
1 added elodea plant and covered in tin foil and placed in dark part of room
1 nothing added to the phenol red covered in tin foil and placed in dark part of room.

after 24hrs results:
the 2 with only phenol red no change to color
the 1 with the elodea plant and light turned pink
(chart says that means it is "basic?")
the1 with the elodea and darkness turned orange which means neutral?

DID CO2 get consumed or released??? I don't get it!
Thanks in advance for any help!

does anyone have the answers to pennfoster biology exam 00765000