Color represents diversity and choice in Lowry's The Giver and these things have been taken away from the people. The idea behind taking color, memories, and other experiences is so that people do not feel pain. The Receiver of the memories experiences all of the pain and suffering for the whole community in order to save them from pain. As with all things, though, there is a price that must be paid for living without pain. Not only does the Receiver have to live with pain, but the people lost the ability to see color in the process. Again, since color represents uniqueness and individuality, that had to be done away with in order to obtain a different result, which is what they consider "sameness."
Jonas first started seeing the color red in an apple, and then later, he saw it in Fiona's hair. Because he was not accustomed to seeing color, he was confused as to what he saw. He didn't tell anyone because they wouldn't understand, but luckily, the Giver understood and was able to teach him how important things like color affect individuality and free choice.
In chapter 11, Jonas also discovers sunshine:
"Suddenly he perceived the word for it: sunshine. He perceived that it came from the sky.
Then it ended.
'Sunshine,' he said aloud, opening his eyes.
'Good. You did get the word. That makes my job easier. Not so much explaining.'
'And it came from the sky.'
'That's right,' the old man said, 'Just the way it used to.'
'Before Sameness. Before Climate Control,' Jonas added" (85).