I had one side go out in my 2011 23FC FB, which for all purposes is just like yours.
Is yours still in warranty? If so, JC will more than likely send you a complete fixture. They sent one to me. Like a dummy (?) I replaced the fixture, and it's not that difficult. However, if I had it to do again, I would replace BOTH LEDs only, and be done with it (assuming yours is a two light fixture).
If it's not in warranty, I would take a picture of the old LED, call Out Of Doors Mart and send them the photo. Then the decision to go cool or warm white would be entirely up to you.