Ionic preview app :(base: #eeae15, contrast: #000) isn't a valid CSS value

Hi, I am trying to use my own custom theme with ionic-preview-app. My scss uses this format:

$colors: (
  primary:    (base: #eeae15, contrast:#000),
  secondary:  (base: #03A9F4, contrast: #000),
  danger:     #f43e00,
  light:      (base:#bdc3c7, contrast:#000),
  dark:       (base:#d35400, contrast:#000),
  alert:      #F39C12,
) !default;

The error I am getting is:

Sass Error
(base: #eeae15, contrast: #000) isn't a valid CSS value.

This SCSS file works perfectly well in my projects and new projects but not in this repo. Any thoughts?

Ionic info:

    @ionic/cli-plugin-cordova       : 1.6.2
    @ionic/cli-plugin-ionic-angular : 1.4.1
    @ionic/cli-utils                : 1.7.0
    ionic (Ionic CLI)               : 3.7.0

global packages:

    Cordova CLI : 7.0.1 

local packages:

    @ionic/app-scripts : 2.1.3
    Cordova Platforms  : none
    Ionic Framework    : ionic-angular 3.6.0


    Android SDK Tools : 25.2.5
    Node              : v8.1.4
    OS                : macOS Sierra
    Xcode             : Xcode 8.3.3 Build version 8E3004b 
    ios-deploy        : 1.9.0 
    ios-sim           : 5.0.2 
    npm               : 5.0.3 

Okay, never mind. Looks like the preview app has not been updated. It uses map-get instead of the colors map that results in this problem. I’ve switched to the ionic conference app that works just fine.