For a €26 adult Sagrada Família visit, morning suits bluer Nativity windows; afternoon suits orange western glass, as the official booklets explain. The Sagrada Família ticket includes the Basilica and museum, with the audioguide app. Sunlight depends on weather and season.
The Nativity façade faces east on Carrer de la Marina; the Passion façade faces west on Carrer de Sardenya. Seeing the Sagrada Família's windows requires no tower ticket.
The final hour of opening leaves you with the express audioguide, which lasts 25 minutes. The Basilica is cleared 15 minutes before closing, so an evening slot needs room for the visit you want.
Plan around: the side whose light you want, with enough time for your visit before the Basilica is cleared.