Thanks! There was some residue there.
I found the primary leak is actually a hose leading to the heater core, but the coolant had dripped down under so it wasn't easy to see. Once the engine started heating up, if I squeezed the hose it would shoot a jet of coolant all over the bottom of the air intake and throttle body, hence the assumption it was coming from that area. It's the hose with the upside-down A on it in the picture. Anyone know the size (it has 69 written on it)?
There is also quite a bit of residue on the metal connector for the driver side throttle coolant hose. If it's easy enough to get too, I'll replace that one too while the plastic air intake is off, maybe the one with the crimp too since it doesn't look too good.