I have seen red in a number of the brighter deep sky objects, ranging from pale pink through to a deeper red. The larger mirrors show it well and especially one that is silvered. To test out whether what I was seeing was real, I once asked a member of the public what colour was the Orion Nebula. I was using a 22" at a public carpark by the Manukau Harbour in Auckland. The sky was pretty dark.
This guy hadn't looked through telescopes before and he never hesitated (without any prompting) to say that the outer edges were pink. Many of the other brighter DSOs like M17 for example can appear pink as well.
Rich
