version_color

# File lib/bundler/source.rb, line 68
    def version_color(spec_version, locked_spec_version)
      if Gem::Version.correct?(spec_version) && Gem::Version.correct?(locked_spec_version)
        # display yellow if there appears to be a regression
        earlier_version?(spec_version, locked_spec_version) ? :yellow : :green
      else
        # default to green if the versions cannot be directly compared
        :green
      end
    end