Just a crazy idea, but just throw a strawberry 🍓 on the package near the flavor name. Boom, solved!
I’m sorry, but “how do you convey a food is strawberry flavored?” is a terrible excuse. Pictures and words like we’ve done for all recorded history. The idea that X taste has to be Y color is an unnecessary human invention. You should be driven more by the content of your food, than how “pretty” it is. Dressing up junk to make it palatable shouldn’t be the end goal.