If it's gummy and red it's probably grease. Many times a CV axle boot will be damaged and allow grease to spray out during high rpms. Check the CV boot for damage. If the boot is damaged it can be replaced as long as the CV joint is good. But if you continue to drive with a damaged boot, the joint will soon fail.
In general, coolant leaks can be deceiving in origin because of two things:
1 - It's mostly transparent so easy to visually miss; and
2 - It tends to leak when the system is hot and under pressure. When cold, even with the engine running, the system is only slightly above ambient pressure (there will be some pressure due to the pumping action of the water ...
That is the head; a part that holds a lifter. It is likely caused by a crack in the sand core and the molten metal conformed to it. It would likely cost most of the price of an engine to replace it if it bothers you. Best guess from the available view.