Are elements a continuum of matter like colors are a continuum of electomagnetic frequency

Yes, they are. But it occurs more discretely

elements are sequentially placed in the table of elements. This would indicate very strongly that indeed elements are sequential as regards to their physical structure and therefore form a "spectrum" if you will.
I dont see how this has any relationship to gravity however. In my own book I explain that gravity is after all, an energy form emitted by each and every atom. Smaller partcles such as electrons, etc., do not have a gravity field since it is the structure and function of the atom which produces the gravity field. Electrons , according to Millikan have a gravity field and therefore will react to the presence of a gravitational filed. In fact however it is the electron's electric field which interacts with the earth's gravitational field. Electrically neutral particles are therefore not affected by any gravitational field.

Do you mean atoms? It doesn't really matter though, the answer is the same either way. No. Atoms are discrete particles made up of other discrete particles. It's possible that gravity is a result of elementary particles called gravitons, but it still wouldn't be a continuum.

No, elements are simply matter, not a continueum of matter.

why? because Matter cannot be created nor destroyed.
Its the constant flow of energy that changes matter.

In other words: Matter is constant, not continued.

Um...............No.