why are galaxies different in color? whether its in movies,television,real-life or some planetarium different galaxies are shown in different color.

For ex:- Milky way is always seen in Blue where as Andromeda gives out a bit reddish color. 

Is it because different galaxies contain different kinds of stars?
Does this effect the life the galaxy harbors...   

^_^
See What do a galaxy's colors mean? Are they its true colors? This article should help answer your question. There's really nothing I can add to the article. It lists all the reasons I could think of.