Normally when you mix red and green you get some shade of brown. However, if you throw blood-red paint and a dehydrated goblin together you get Hemogoblin.
Hemogoblin is a zenishift that can show up as a rusty iron-like oxidized heme or as a color any greenskin would be proud to wear. This is certainly an unusual pairing, begging to be used on something that goes bump in the night.
Note: Over white, Hemogoblin is a bright orange. Over black, it is olive.