For this design, I used China Glaze Immortal from the new Halloween collection on the fourth finger and China Glaze recycle on the rest of the fingers. You don't necessarily need a different color for an accent nail. Also, any medium to medium-dark color will do for these nails. Blue, green or even purple would look really pretty with the design. Just make sure that the color you use is not too dark as to hide the black that you will need for the cat silhouette.
Apologies for the slightly blurry photos. The lighting was just not agreeing with me today.
Thanks for visiting.