Captain Numpty things have changed with the FAA. The SODA is no longer required. If you pass the signal light test you are now issued with a letter of evidence which states that you meet the standards set out in part 67 of the FAR's, (keep it to show the next AME) this is the same as if you had passed one of the other tests with one small difference. The FAA will keep a note on your records under pathology for defective colour vision. This may or may not be a problem when you apply to a major airline that does a check on all you records. strictly speaking they are not allowed to discriminate against you but who knows. As to having this removed from you records all you have to do is pass one of the other approved tests and the FAA will remove it for you. In fact the FAA prefer if you had passed the signal light test first, because they are very comfortable with the signal light test (100% Safety record) but some of the people that pass the other tests can actually fail the light gun test, In studies conducted by the FAA it rages from around 1-2% for the FALANT and the titmus to around 5-6% for the ishihara and devorine plates.
If you had some trouble getting a SODA removed contact AOPA(US) they are experts in dealing with the FAA on this and other medical issues.