Looks like it is scratched down to the Primer.
There is a Paint color code number on the drivers door label, you can often get color "sticks" from a Ford Dealer that includes a small brush, but getting a smaller tip brush is also a good idea.
These 'sticks' are not cheap, expect to pay $25-$35, this is a lacquer paint same that is on the truck now.
You need to fill in the scratch first, you can get a spot putty from most auto parts stores, you fill in the scratches and remove the rest, let it dry and then paint it.
Simple steps here: How to touch up a deep paint scratch in your car.