Plugs have red oily stain and misfire

[zukitrek]

Here it is same brand but different gas. Remembered that I mentioned my red gas was Shell 87. So my guess regular is that red/light pink color because and Premium is what you were expecting. At least in that gas station their two types. Have a look.

In the sun

   

In the shade

   

Hope this clears your doubts about gas color here in PR.

Regards!!!