Right click on your speakers, click advanced, go to the enhancements tab, and try unchecking all of them if there are any.
Try swapping the cables around, I had some weirdly colored speakers a while ago and I'd just keep switching the cables between the different slots until I heard sound.Is your sound card integrated into your motherboard with the 3 sound ports (blue green and pink) or do you have a separate sound card? If you have a sound card can you tell us what model of sound card you have?