I used Klean color Shining Sea-218 and Metallic Sapphire-165 for most of the nails and Metallic Pink-158 and Metallic Purple 167 for my ring finger and thumb.
I wished I had used my Metallic Aqua instead of Shining Sea and in fact I had meant to, they look very close in the bottle but I didn't check. Shining sea is a fine glitter so I think it absorbed some of the Sapphire so it didn't give as strong contrast.
I started with 2 coats of Shining Sea and Metallic Pink and let those dry completely. I then took sponge and painted some of the Metallic Sapphire and sponged it on the tip of the nails with Shining Sea. I used same method to sponge Metallic Purple on the tips of those nails with Metallic Pink.
I then used the Knock Off XL Plate K to stamp Color Club Harp On It -976 over the accent nails.
The holo stamped well but it was very subtle and only showed in just the right light . I did do both hands but I was in hurry to get out the door so I only got a shot of the Left Hand. The blue gradient was hard to get pic of you can sorta see it but not super well.
I also cut the makeup sponge in half vertically to minimize the clean up. I really do love this gradient.