MoonShadow: We have a lot of CDs lying around the office. On a sunny day, the entire ceiling is covered with swirling, shimmering patterns of colour. It is very soothing to watch while I'm waiting for everything to recompile.
AlexChurchill: My workplace doesn't contain much rainbow-coloured :( Except for the six JellyBeanieBabies sitting atop my monitor. But when I moved into my house, the built-in wardrobe with seven compartments was painted this garish red. We repainted the room purple, but the wardrobe (particularly its top compartment) would have been difficult to paint. So we left that one red, and painted the other six orange, yellow, green, sky blue, indigo, and purple. I now have a Rainbow wardrobe :)
StuartFraser: At home, my CD racks are next to the window, producing an effect on my room similar to that in MoonShadow's office. Today I encountered a friend who had a Rainbow umbrella. This meant that she was actually excited by the rain, because she could use it. It is cool.