I am 5'5", 145", 38 at the hip and wear a size 6 jean and the Medium fit perfectly.  There is an elastic waistband in the back that could help accomodate a J-Lo booty but this size on me wouldn't accomodate much.  If you are more ample in the rear or wider in the hips, I would size up one size.  The colors are exactly as pictured.