As the photo shows, I wonder how do I connect them back in correct sequence, black-white-green-red?

I want to upgrade my memory into 2.5G,but problem seems they are not compatible. while added the additional 2G memory the...

Thanks David, I ordered the exact same standard as it required.Here's what the seller described, http://cgi.ebay.com/NEW-2GB-Apple-iMac-G5-1-9GHz-17-iSight-Memory-RAM_W0QQitemZ350241793689QQcmdZViewItemQ... It's a Kingston for iMac533 model. Will it depend on the operation system?Mine's still in Tiger