[Rick Parker]

Is it possible that by adding water or the premixed 50/50 to the straight coolant that it "diluted" or weakend the color. One of the craziest things I have seen in recent years is the marketing of what is "advertized" as premixed 50/50 coolant. It seems to be about $1.00 - $1.50 less per gallon. That doesn't "pencil out" for me.

Several years ago on this site there was exhaustive discussion regarding various coolants and their use in our varous engine combinations. It was ultimately determined that some coolants are not compatable with the some of the performance gaskets (there were several failures).
Many of the OEM automakers use gaskets that have a plastic like support (frame) and utilize rings made from a "rubber like" material that create the necessary seal.