Looks like rust under the paint. The hood will need blasted to bare metal and epoxy primed and repainted with good stuff. Call these folks. These Folks
Wire wheel paint off till you hit shiny steel then por or Eastwood rust encapsulator. Make sure you prep with recommended products by encapsulator manufacturers. Looks like you will be making a few tech line phone calls.
they apply it more as a preservative than a paint prep, but evidently it works as that too. basically they use it to spot treat rust from spreading further so that they don't have to do full blown blast/wire wheel and prime/seal on small areas.
might be worth investigating if you're not looking to repaint a whole section of the car and you're fine with just having a driver.
I'm a fan of rust mort. You remove hood so area facing up. Spray let sit. Take a nickel and if you can scratch into the rust you keep adding coats until you can't, then rinse with water, dry and it's ready for prime and paint. It will also get into area's you can't. A pint should be enough for that. I believe you can find a YouTube video. Amazon product ASIN B000K21KR0