Did the late 77-79 Trans AMs ever come from the factory silver with the orange/red firebird on the hood?

The color of the screaming chicken would have mostly depended on the interior color.
If you had a silver TA with red interior then yes it could have come with the orange/red
decal if the interior was blue the decal would have matched that.
Generally the rule, not always. A blue TA with tan interior could have either
a blue or brown decal.

sounds like a 10th Anniversary Edition Trans Am