Which macromolecules were present in each of the samples?

Answer: Color After Iodine Test, Color after Copper...
Water: Brown, Blue
Potato: Dark blue - black, Blue
Egg White: Brown, Purple
Milk: Brown, Purple
Unknown: Brown, Purple
But I don't know the question to number one...
Explanation:
Don't really have an explanation but I got the answers during class, so I know these are right