I made one for my first grandchild 2 years ago and am currently working on another. My son and daughter both chose not to know whether they were/are having a boy or girl. The first quilt for my granddaughter I made using the "Love Is" calender from 2008. I used the pictures from 4 calenders I purchase on clearance. For the remaining squares I used a seafoam green and gold. It turned out quite nice. I have since purchases a "Love Is " panel that has the same pictures. This will also be green and gold since my daughter doesn't know if it is a boy or girl.
I don't think pastels and pink and green are absolutely necessary for baby quilts. Sometimes slightly darker more intense colors add something extra to a babies room. I have also completed one for a boy using gold and several medium to dark blues.
Just do what you like, or the parents like.