Knowing my luck, it could be trans fluid. But, it doesn't matter either way. Whatever is leaking from that location, is not repairable. Where that line goes into, is what'* called a quick disconnect fitting. If you slide the plastic clip back down the line, you will see a little C-spring clip inside the housing. Once that is out, the line will pop right out. Now, that quick disconnect fitting is removable from the radiator. It could be as simple as replacing that quick disconnect fitting. But this kind of requires special tools to accomplish. Unless you are savvy in a tool box, you could figure it out.
I suggest taking it to a reputable shop(NOT A QUICK OIL CHANGE SHOP!!) and have them take a quick peek at it.
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