Prayers for you and your grandson.

I doubt there is anything to worry about, it could be normal. It is not uncommon for babies to spit up discolored mucus, I have seen newborn baby's cough up all sorts of nasty looking stuff.

Did she have a C section or deliver him naturally? If she had a C section, sometime all the nasty stuff is not expressed from the airways and it comes out later. Natural delivery squeezes that nasty stuff out as they come through the birth canal.

The color of a mother's first milk, known as colostrum, is typically yellowish or light brown color.

Depending on the baby's lung sounds at birth, respiratory effort and secretions in the airway, often they suction the baby's airway using a catheter to remove secretions. This could cause some slight trauma, and some small amount of blood may be present later, it is nothing to worry about.

Was there any meconium in the in the amniotic fluid when the baby was born?

Sometimes, the baby can have a bowel movement in utero. (meconium).

That stuff is like tar. If it gets in the lungs, things go bad really quick.

However, if it happens during the labor process, the lungs may not be affected, and you got lucky. It may get in the mouth, oral airway and on the skin. It doesn't cause any issues oxygenation or ventilation, but it could discolor the saliva if the hospital staff do not get it out. Not that the hospital did anything wrong, like I said, it is like tar, you can't remove it, it is something that happens over time.

I have worked in the NICU/PICU for close to 30 years. Present at the beside for countless deliveries and C sections. Babies coughing up nasty looking stuff is normal, that is what they do, don't worry yourself.