You can search "DuoTone Blue Black" in the setting menu.
Or you can also execute this in the terminal.
apm install duotone-blue-black-syntax
I am a student. Studying Computer Science at Hanyang Univ.
p.s. Here's my setup with native-ui and futura font
Good catch. Let us know what about this package looks wrong to you, and we'll investigate right away.