Don't you feel like it's a little more Christmas-ey when you unroll a string of multi color lights?  When we took photos of these multi lights everyone in the office couldn't help but smile and comment.

<I think multi color lights bring out the kid in each of us.>

These lights have a single plug and are tailored for use with projects where you have no need to run lights in series and you need a set that has just a single plug.