Why is one 340 connecting rod bronze color?

Just remembered something from my steel melt shop days.
Copper IN steel (too high) is about the only thing that cannot be fixed while the heat is in the furnace.
Not many times, I saw heats of steel downgraded for copper, but it happened.
If it were too high for any grade, it would have to be scrapped and recharged in smaller parts.
Copper must be diluted out of steel,
no other process or addition will subtract it.