Failed to reload the styleguide package stylesheets

[jasperandrew]

Steps to reproduce:

1. Install cake-syntax
2. Install nucleus-dark-ui
3. Set both in settings, in either order.

Atom: 1.16.0 ia32
Electron: 1.3.13
OS: Microsoft Windows 10 Home
Thrown From: styleguide package 0.49.3

Stack Trace

Failed to reload the styleguide package stylesheets

At error evaluating function `mix`: color1.toHSL is not a function in C:\Users\Jasper\AppData\Local\atom\app-1.16.0\resources\app.asar\node_modules\styleguide\styles\variables.less:69:2

LessError: error evaluating function `mix`: color1.toHSL is not a function
  at /app.asar/node_modules/styleguide/styles/variables.less:69:2

Commands

     -1:09.3.0 tree-view:show (atom-workspace.workspace.scrollbars-visible-always.theme-cake-syntax.theme-nucleus-dark-ui)
     -0:34.7.0 core:confirm (input.hidden-input)

Non-Core Packages

aurora-theme 1.2.2 
autocomplete-haskell 0.7.2 
cake-syntax 1.0.2 
file-icons 2.1.3 
gruvbox-plus-syntax 1.3.1 
haskell-ghc-mod 1.19.9 
javascript-snippets 1.2.1 
language-haskell 1.12.1 
language-lua 0.9.11 
language-prolog 0.10.0 
language-r 0.4.1 
language-x86-64-assembly 2.2.8 
nucleus-dark-ui 0.11.17