If you click on the picture to blow it up, you will see the gold works the best for blending. This is a shirt for Q, and I was going to do the blue until I previewed it and have since decided on the red. When I first started sewing, I chose the closest blending color, but now I often choose a color to show off the topstitching. For piecing a quilt top, I don't really care what color I use as long as it doesn't call attention to itself and will often choose gray. For quilting the top, it depends on whether or not I want the quilting to disappear into the top to show off the quilt or to call attention to itself. Sometimes I will chose a color that pulls the whole quilt together if it needs that.
