I sympathize BB.  Four hours myself, ergo a stupid question to begin with.  One look into "Amateur Telescope Making", while old is filled with good numbers, including the reflectivity of the different common mirror platings.  Duh!  What isn't reflected is the amount that is absorbed, Oh, well.  Headbone some other kind of defensive armour.

Color of mirror:  If you look at thick plate glass edge on, you see a green color.  This would affect a second surface mirror, but not a first surface.  First surface, each coating has it's own band of strongest reflection, the reflective coating would determine what the color would be.  What is overcoated on a first surface mirror has different purposes, including reflectivity.

D.

The "I" in Doric is Silent.