Orange or Green Anti freeze?

NEVER EVER USE DEX-COOL! The stuff is terrible with aluminum! Nearly every manufacturer out there with the exception of GM (go figure) warns against using it. There have been numerous articles written in the trade magazines about its harmful effects. I can testify personally to a case where a customer had been using it in his car and in 2 years it ate away at the engine block and pitted the head so bad it had to be junked because there was so much damage that there was enough surface for the head gasket to seal against.
Green is fine with aluminum. So is the global type and the red or pink stuff.
And as Rusty Rat Rod said you have to change whatever you put into it often enough.