Mix doesn't output the same value as vanilla SCSS

• polished version: 4.1.0 and 4.2.2
• JSS-in_CSS library and version: styled-components 5.2.1
• Any relevant JS library and version: React 16.0.0

Mixin/Helper/Shorthand Usage

mix(0.80, '#000000', '#A4A8B1')

What You Are Seeing

Output exa value: #202123

What You Expected To See

With vanilla SCSS

mix(#000000, #A4A8B1, 80%);

The output exa value is: #212223