I did this nail art weeks ago but didn't have time to write about it. It's really cute if you don't look at it too close.. Wtm.. I just bought myself a set of dotting tool and I tried them out with this nail art. Pretty fast and easy compared to drawing hearts with a brush, especially lots of hearts.
As for the colour, even easier. Started with red at the tip of the nail and then add little white towards up. So, dotting tool wins!