Testing this is a bit of madness due to isatty

lib/foreman/engine/cli.rb

@@ -30,6 +30,12 @@ def self.enable(io, force=false)
     end
 
     def color?
+      $stderr.puts "@@color_force: #{@@color_force.inspect}"
+      $stderr.puts "Foreman.windows?: #{Foreman.windows?.inspect}"
+      $stderr.puts "self.respond_to?(:isatty): #{self.respond_to?(:isatty).inspect}"
+      $stderr.puts "self.isatty: #{self.isatty.inspect}"
+      $stderr.puts "ENV['TERM']: #{ENV["TERM"].inspect}"
+
       return @@color_force unless @@color_force.nil?
       return false if Foreman.windows?
       return false unless self.respond_to?(:isatty)

spec/foreman/cli_spec.rb

@@ -56,6 +56,31 @@
         output = `bundle exec foreman start -f #{resource_path "Procfile.bad"} && echo success`
         expect(output).not_to include 'success'
       end
+
+      it "successfully enables color control chars, by default" do
+        allow_any_instance_of(Foreman::Engine::CLI::Color).to receive(:isatty).and_return(true)
+        fake_term_value = 'xterm-256color'
+        output = `env -- TERM='#{fake_term_value}' bundle exec foreman start -f #{resource_path("Procfile")}`
+
+        expect(output.scan("\x1B")).not_to be_empty
+      end
+
+      it "successfully enables color control chars, when specified" do
+        allow_any_instance_of(Foreman::Engine::CLI::Color).to receive(:isatty).and_return(true)
+        fake_term_value = 'xterm-256color'
+        output = `env -- TERM='#{fake_term_value}' bundle exec foreman start -f #{resource_path("Procfile")} --color`
+
+        expect(output.scan("\x1B")).not_to be_empty
+      end
+
+      it "successfully disables color control chars, when specified" do
+        allow_any_instance_of(Foreman::Engine::CLI::Color).to receive(:isatty).and_return(true)
+
+        fake_term_value = 'xterm-256color'
+        output = `env -- TERM='#{fake_term_value}' bundle exec foreman start -f #{resource_path("Procfile")} --color=false`
+
+        expect(output.scan("\x1B")).to be_empty
+      end
     end
   end