How should I wire this ceiling light pendant?
Both black and red are typically used to indicate hot.  Though you can't be positive without actually testing it with a multimeter.  Red is usually used when there are two hots (14/3 wire instead of 14/2).

Both green and bare copper are used to indicate ground.

So it sounds like you wired it correctly.  The green wire from the line (source) should also be attached to the green grounding screw in the electrical box.