Yesterday I decided to do a drain and fill on Frosty, at 200k I don't really want to have it flushed. The coolant in the reservoir looked pretty red, and what was draining out looked pretty red too. So I let it drain and went and picked up a couple jugs of Peak Asian red from Auto Zone. Closed the drain and filled the radiator, let it run and burp for a bit and called it done. Drug the drain pan out and dang if it isn't orange and not red. About 10-12 years ago I let the service manager at the shop I used to take it to talk me into a coolant flush, they must have used Dexcool since it's a Pontiac.
I had some dexcool on the shelf from a car my son used to own, so I mixed a few ounces each of the red and orange in a cup to see if there was any sign of gelling. This morning it was still good, but I did another drain/fill today just to remove some more of the Dexcool. Also bought a no-spill funnel
https://www.amazon.com/OEMTOOLS-87009-N ... 136&sr=8-1. It was 40 bucks at Auto Zone and worth every penny, but I wish I had thought of it ahead of time and bought one from Amazon for $25.