rg = /^(?=[\da-f]$)/,
ISURL = /^url\(['"]?([^\)]+?)['"]?\)$/i,
colourRegExp = /^\s*((#[a-f\d]{6})|(#[a-f\d]{3})|rgba?\(\s*([\d\.]+\s*,\s*[\d\.]+\s*,\s*[\d\.]+(?:\s*,\s*[\d\.]+)?)\s*\)|rgba?\(\s*([\d\.]+%\s*,\s*[\d\.]+%\s*,\s*[\d\.]+%(?:\s*,\s*[\d\.]+%)?)\s*\)|hsb\(\s*([\d\.]+(?:deg|\xb0)?\s*,\s*[\d\.]+\s*,\s*[\d\.]+)\s*\)|hsb\(\s*([\d\.]+(?:deg|\xb0|%)\s*,\s*[\d\.]+%\s*,\s*[\d\.]+%)\s*\)|hsl\(\s*([\d\.]+(?:deg|\xb0)?\s*,\s*[\d\.]+\s*,\s*[\d\.]+)\s*\)|hsl\(\s*([\d\.]+(?:deg|\xb0|%)\s*,\s*[\d\.]+%\s*,\s*[\d\.]+%)\s*\))\s*$/i,
rg = /^(?=[\da-f]$)/,
ISURL = /^url\(['"]?([^\)]+?)['"]?\)$/i,
colourRegExp = /^\s*((#[a-f\d]{6})|(#[a-f\d]{3})|rgba?\(\s*([\d\.]+\s*,\s*[\d\.]+\s*,\s*[\d\.]+(?:\s*,\s*[\d\.]+)?)\s*\)|rgba?\(\s*([\d\.]+%\s*,\s*[\d\.]+%\s*,\s*[\d\.]+%(?:\s*,\s*[\d\.]+%)?)\s*\)|hsb\(\s*([\d\.]+(?:deg|\xb0)?\s*,\s*[\d\.]+\s*,\s*[\d\.]+)\s*\)|hsb\(\s*([\d\.]+(?:deg|\xb0|%)\s*,\s*[\d\.]+%\s*,\s*[\d\.]+%)\s*\)|hsl\(\s*([\d\.]+(?:deg|\xb0)?\s*,\s*[\d\.]+\s*,\s*[\d\.]+)\s*\)|hsl\(\s*([\d\.]+(?:deg|\xb0|%)\s*,\s*[\d\.]+%\s*,\s*[\d\.]+%)\s*\))\s*$/i,