Betis lost star player Dani Ceballos to Real Madrid earlier this summer, but the Seville-based side have been active in the transfer market, signing Mexican worldwide Andres Guardado, former Barcelona winger Cristian Tello and ex-Manchester City midfielder Javi Garcia.
Aside from the shirts, Barcelona is planning a minute's silence before the match on Sunday.
Rivals Real Madrid began their pursuit of back-to-back league titles for the first time since 2008 with a 3-0 win at Deportivo La Coruna with goals from Gareth Bale, Casemiro and Toni Kroos, although captain Sergio Ramos was sent off in the dying seconds, earning a 23rd career red card.
And he preferred to focus on these fine performances when asked about transfers following the 2-0 win, responding: "I can only talk about the players I have here".
Zidane made four changes from the side that completed a 5-1 aggregate hammering of Barcelona in the Spanish Super Cup on Wednesday.
Barcelona started their 2017-18 La Liga campaign with a 2-0 victory over Real Betis at Camp Nou on Sunday night.
Twin terrorist attacks on Thursday killed 14 people and wounded around 120 in Barcelona's bustling Las Ramblas thoroughfare and the nearby seaside resort of Cambrils.More news: Furor Over Trump's Charlottesville Remarks Raise Fears of a Stalled Legislative Agenda
After the attack some fans, especially tourists, returned their tickets, the club said without giving figures.
"They are extraordinary and lamentable circumstances", said Valverde on Saturday. After the loss of forward Neymar to the French club Paris Saint Germain, their will be even more pressure on Messi and Suarez to keep up the goal scoring that has defined Barcelona's play.
On the field, Valverde's reign got off to a hard start with a 5-1 aggregate thrashing in the Spanish Super Cup at the hands of rivals Real Madrid.
Barcelona coach Ernesto Valverde also offered his support for the victims of the attacks. "Our idea was to be able to dedicate this victory to those affected".
The hosts eventually broke the deadlock in the 36th minute when Deulofeu delivered a low cross into Messi, although the Argentine's shot was deflected into the net by Betis' Tosca.
To make matters worse for the visitors, Barca went right down the other end and doubled their lead through Sergi Roberto.