Was topping off my oil, and grabbed the wrong jug. The jugs are similarly colored and I am colorblind. I put maybe a half cup of concentrated coolant in the engine, and when seeing the green color, immediately drained the engine oil, then took the remaining new oil I had, maybe half a quart, and poured it through. Anything else I should do before adding new oil?

 

might wanna run really cheap dino oil through it with some detergent agent for a bit, then drain and refill with the oil of your choice.

 

Yup, that'll do it. Make sure it's detergent. Run it for long enough to warm up. Do not rev it, just idle. Change and refill as normal.