You just need:-
-beige nail polish(grayish)
-scotch tape
-black and golden nail polish
-clear top coat.
Steps:-
1. Apply a beige nail polish to your Nails and then let them dry for few minutes.You are free to apply more than a coat if needed.
2. Once dried place two pieces of scotch tape by forming an upside down triangle at the tip of the nail such as shown in the picture.
3. Fill the triangle with black nail polish and wait few minutes to dry.
4. Place the corner of a scotch tape in the mid of the black triangle and then paint the space in between with golden nail polish.
5. Remove the tape and then apply clear top coat.