Unfortunately, when using hashes as values you also need to use colons. So, instead of
.best-thing-ever
width 1234px
color colors['white']
font-size 23px
you would write
.best-thing-ever
width 1234px
color: colors['white']
font-size 23px
Note that the colon is only needed for properties that have hashes as values. See this related issue on GitHub for details.