Yes! Of course apple syrup would be acceptable! Because it’s syrup! And light or dark doesn’t matter.

Here is the rule for putting something sweet and flavorful on a waffle-

Is it a sauce? Do not put it on a waffle.

Is it flavored butter? Do not put it on a waffle.

Is it syrup? Put it on a waffle.

Look, I didn’t invent these rules. This is in the constitution.

Edit: Creams of the whipped variety are also allowed.