Spotify's new brand identity is full of bright colours. Here is the same effect but for iOS.

Code: https://github.com/72lions/Duotone-iOS

One of the ways to achieve this result is the well known duotone process where you pick two colours (one for the highlights and another for the shadows) and you replace all colours in the picture with these two.

Sounds simple, right? Well it is. You can read more about the process in a previous post where I describe the effect in JavaScript.