Once again I am going to recommend that you go back to the Navy's Damage Control reports on the Vestal. The information regarding the decks is contained there.
http://www.dcfp.navy.mil/cgi-bin/WarGalleryPop.cgi?id=47
In my opinion (that and 5 bucks will get you a cup of coffee at Starbucks), the Vestal was not in Measure 1, in either Dark Gray (5-D) or in Sea Blue (5-S). Based on the above photo, the mast tops above the funnel line were not painted a lighter color. Measure 1 called for these to be Light Gray (5-L). Rather the ship appears to be relatively uniform. Painting regulations also called for yard and district ships and craft to be painted in Ocean Gray (5-O). I believe the Vestal was in Ocean Gray.
http://www.dcfp.navy.mil/cgi-bin/WarGalleryPop.cgi?id=46
The starboard side coloration is similar