I wouldn't worry too much about the color of the old oil, and just worry about the OCI. From my research across Ecoboost F150's SHO's and MKS's, 5K OCI's are where you want to be. After reading numerous Blackstone reports from 3.5L Ecoboost vehicles at 5K, the oil additives are still there, and people are seeing good wear numbers, but Blackstone recommended not going too much over 5K. At 3K, they said it was beyond overkill, and to extend out to 5K. More than that, I am not so sure. I have changed my oil twice, on a 5K OCI, and I am now running Pennzoil Platinum 5W 30, but with the Motorcraft FL-500 filter. I do believe on these Ecoboost engines, the FL-500 is the best filter, not only due to the bypass valve PSI, but they are well constructed and only $6. Some folks were hearing more startup noise with other oil filters, even at the same relief valve PSI.