Metallic color on the bottom of transmission pan? Not Metal shavings.
 

So today I changed the trans pan gasket and when I dropped the pan the bottom of it had a layer of what look and felt like grease to me. I couldn't feel any metal shavings in it and it had no shine to it. Just looked like metallic looking grease. The car shifts great, and has absolutely no problems driving at all (now). Could it be because it had a transmission rebuilt in the past possibly?

Could be some sort of transmission slip fix stuff. Or something similar not sure

JW what you are describing sounds normal, nothing to fear. I've done a few pan drops and sitting in the bottom of the pan (that I clean out with a paper towel) is some crud that looks like trans fluid with a metallic substance. Also on each trans pan I have dropped, it has a small magnet glued in the bottom.

As I understand, by definition of normal usage, the transmission will generate a very fine metallic substance (it's from the different components doing their jobs). This is part of what the filter collects and that magnet and another reason why you should periodically change your trans fluid and filter on a regular and recommended interval for your driving style and conditions.

When doing a trans filter and fluid change, I always throw a can of lube guard in it.