On my top tier, I covered it with white fondant 1/4 thick. I can see the strawberry cake through it. I have never had this problem before.
How can I remedy this without starting over? Could I just add another layer of fondant over it?
Absolutely. You can even use small cookie cutters to cut into the top fondant and give you a "relief" type look. Sounds like your crumbcoat wasn't thick enough to mask the color of your cake. Next time make the BC coat thicker so you can't see the cake underneath and then cover with fondant. HTH