Sass supports a number of value types, most of which come straight from CSS. Every expression produces a value, variables hold values. Most value types come straight from CSS:

  • Numbers, which may or may not have units, like 12 or 100px.

  • Strings, which may or may not have quotes, like "Helvetica Neue" or bold.

  • Colors, which can be referred to by their hex representation or by name, like #c6538c or blue, or returned from functions, like rgb(107, 113, 127) or hsl(210, 100%, 20%).

  • Lists of values, which may be separated by spaces or commas and which may be enclosed in square brackets or no brackets at all, like 1.5em 1em 0 2em, Helvetica, Arial, sans-serif, or [col1-start].

A few more are specific to Sass: