With that in mind, for an engagement session, I highly recommend that as a couple, you both wear darker colors with long sleeves. This helps to keep the attention on your faces and away from bare arm distractions. The colors should be in the same color family and preferably navy, denim, green, brown, red, or black. You'll want to stay away from pastels.
Also avoid colors with patterns, such as stripes, checkered, etc. Stay with solid colors.
Don't forget--dark, solid, same color family, long sleeved clothing will work best to help me create that perfect engagement photograph!