In modern culture, yellow roses apparently represent joy, gladness, freedom and contentment. However, in Islamic folklore the meaning is really quite different. It is believed that the yellow rose is a symbol of deceit, treachery, and adultery. Obviously these are quite different interpretations of the same thing, which show the transitional nature of color symbolism and representation theory.
"We must assume every event has significance and contains a message that pertains to our questions. This especially applies to what we used to call bad things. The challenge is to find the silver lining in every event, no matter how negative." -- James Redfield