How to use regular expressions to match and replace more complex html tag？

Question

How can I use regular expressions to match all tags with a style attribute and a color value, then extract their color value and replace the tag with <color=colorValue>content, please help me, thank you

//original tag
// <p style="color:#ffffff;">content</p>
// <span style="color:#ffffff;">content</span>
// <i style="color:#ffffff;">content</i>
//...


// expect replace tag
//<color=#ffffff>content</color>

Answer 1

const regex = /(?=.*style="color:(#\w+?);")<([a-zA-z]+)[^>]+>(.+?)<\/(\2)>/gm;

const str = `//original tag
// <p style="color:#ffffff;">content</p>
// <span style="color:#ffffff;">content</span>
// <i style="color:#ffffff;">content</i>
//...


// expect replace t
//<color=#ffffff>content</color>
`;
const subst = `<color=$1>$3</color>`;

// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);

console.log(result);

//output
//original tag
// <color=#ffffff>content</color>
// <color=#ffffff>content</color>
// <color=#ffffff>content</color>


// expect replace t
//<color=#ffffff>content</color>