Build, test, and debug regular expressions
This regular expression is designed to match SCSS or Sass variable declarations, specifically targeting short values typical of color codes like hex values. It captures the variable name, its assigned value (between 4 to 7 characters), and an optional `!default` flag. It is particularly useful for extracting or auditing color variables and their corresponding values within stylesheets. Note that the value length constraint might cause it to miss longer color formats like `rgb()` or named colors.