< font color=‘red’ >hello sweety< font >

It is possible but you need to change the current module code as well, right now it is creating text node but to support html text code needs to be changed as below

for (var part of parts) {
			// create a text element for each part
			//compliment.appendChild(document.createTextNode(part)); //Comment this line
			compliment.innerHTML += part;  //Add this line
			// add a break `
			compliment.appendChild(document.createElement("BR"));
		}

Result should be as below if your compliments are like below

evening: ["Wow, you look hot!", "You look nice!", "Hi, <i>sexy!</i>","< font color='red'>hello sweety< /font>"],

–
Ashish