For the particular S-3B Viking VS-29 that took part in OIF shown below, SuperScale Decal Sheet 48-951 calls for an overall color of FS 36320. I thought low viz S-3B Vikings are painted FS 36375 overall. Is this aircraft a special case?
Some pictures of this aircraft can be found at https://www.midwaysailor.com/midwayhangar/viking.html
It does appear to be an overall Dark Ghost Gray on my computer monitor from the photos.