K8WE Motherboard (S2895) and Onboard Sound with Logitech Z-5500 Speakers

Hi,

I am trying to hook the onboard sound up to some Logitech Z-5500
speakers. I have an Orange, Black, and Light Green 1/8 mini-jack. I
have two major problems. First, the 1/8" mini-plugs don't fit into the
motherboard, and (b) the outputs aren't correct for the three jacks I
have.

I thought this motherboard had multi-channel audio, but I can't figure
out how to get it?

Thanks!

Jim