Your link seems to be discussing paints that reduce conductive losses (paint with insulating additives) between the paint and the ambient air, whereas I believe

Your link seems to be discussing paints that reduce conductive losses (paint with insulating additives) between the paint and the ambient air, whereas I believe the person you were responding to was describing paint that optimized radiant losses between paint and the visible sky and reduce reduce gains from the sun, which are independent of ambient air temperature. For example, there's a reason so many buildings in the Mediterranean are painted white going back to antiquity.