Cu2+ is a strong, linear holo teal polish. The formula is quite dreamy! It just glides smoothly over your nails and provides full coverage with just 1 coat!  I must say this polish had me perplexed for a bit. The polish first looked blueish to me and I couldn't figure out why it was names after copper. But, after observing it under different lighting I do see is more of a teal green than blue. 

Shown below are 2 coats (just for good measure!) with no top coat. I used Silver Sweep from Sally Hansen and Pueen encore plate SE01A on my accent nail.