By the way, this is the code that I ended up with in case anyone needs it. A checked Boolean field turns the box black, a false one turns it yellow.
$w.onReady( () => {
$w("#dynamicDataset").onReady( () => {
let itemObj = $w("#dynamicDataset").getCurrentItem().creases;
if(itemObj===true){
$w("#box2").style.backgroundColor = "#ffff";
console.log("it's true");
}
else{
$w("#box2").style.backgroundColor = "#ef0";
console.log("it's false");
}
} )
} );