You might consider getting rid of both... or just hanging them on the wall for artwork. And instead just get a new bike.
I do endorse the suggestion to keep the one that will be your first choice for a long ride or the rides that you normally do. Choice by color appeal comes in a close second.
However I will say that my new, or fairly new 2020 Tarmac is the most fun bike I've ever ridden. Not that my other bikes weren't good comfortable rides, but the new bike is like a sports car compared to luxury sedans.