The film opted for a bleached, "heavy metal" aesthetic to reflect a world devastated by nuclear war.
An original script concept had John Connor dying and having his skin grafted onto Marcus's body to keep the "legend" of John Connor alive—but this was changed before filming. Terminator Salvation(2009)
The franchise creator didn't find the movie "bad" or "embarrassing," but felt it didn't push the series far enough beyond its established boundaries. The film opted for a bleached, "heavy metal"