Ferrofluid has a very unique property. It is magnetic, caused by the millions nano iron particles in it. When put under a magnetic field, the particles in the solution start to rearrange due to the attraction and repulsion of iron. If now water colors are added to the ferrofluid, the pop-art looking structures start to appear, forming into black channels and tiny ponds filled with rainbow colored surfaces. The reason why the black ferrofluid and the water colors don’t mix is that ferrofluid is, just like oil, hydrophobic.