I want to take a painting class at a local art school to further my painting skills.  Does anyone know what type of paint properties GEL FOOD COLORS most resemble? 

Acrylics, Watercolors, Oil, other?

I think they most closely resemble watercolors, but they are not exactly like them.  I think any painting class will improve your cake painting skills and I hope you enjoy the class!

The gel food colours can be diluted with different media--vodka, piping gel, corn syrup.

That gives then significantly different qualities.  Vodka--most like watercolour.  Piping gel--most like acrylic.