I don't have any problem putting colors together, I probably tend to make things to matchy-matchy. My advise would be to lay different fabrics side by side, switch them around, take your time looking at them. I am right now trying to decide on 5 different blues, from dark to light, for a king size dresden plate quilt I want to make for myself. I also take swatchs to the fabric store when I need to match something.