STL files describe only the surface geometry of a three-dimensional object without any representation of color, texture or other common CAD model attributes.
What difference does it make? Both have some color applied to the faces. You can easily do that.
I would also check the specs of the printer you are using, full colour printing can get a bit tricky, not all printers were born equal.
I would base your colour choices on the printer you know you are going to use as the existing colour printers use different techniques to varying levels of finishing.