My friend has a 91 eclipse GSX and we were looking at the engine block, instead of it being black its red. the whole block is red in color? My question is, is this some kind of special block or do you think it was just painted?

The block? Unless I'm mistaken, they are uncolored from the factory. I'd guess it's just been painted.

the one in my 98 GST is Black.

Well, is the head also red? THAT isn't painted.

no, the head isn't painted, just the block

Somebody Painted the engine... maybe when they swaped it (if it was broken... I never heard of an 91 engine that came red stock... my 95 came stock broken... but nothing else)

mines not painted . maybe it's a specially rebuilt one :p I might powder coat mine on my rebuild.
but, no I haven't seen one that way stock, even in a eagle.