Dice vegetables; mix dressing and vinegar together in a large bowl. Add vegetables and marinate in refrigerator several hours or overnight.
Cook pasta; cool thoroughly. Add to dressing and vegetables; toss well to mix. Refrigerate until ready to serve.
MY NOTES: When just my husband and I are eating this, I add the spinach; however, my son and grandson will not eat it, so I didn't add it to what is shown in picture. We do not like feta cheese, so I did not add it.