On Friday, owner Vincent Tan reversed his decision to rebrand the Championship club red in 2012.
That met with approval from many Bluebirds fans, who had campaigned for a return to traditional club livery.
"It gave them [the fans] something to cheer about," said Gunnarsson, who set up Sean Morrison for Cardiff's goal.
"There's not been much to cheer about lately and it gave the fans a boost.
"They want to see us in blue and the owner has done the right decision."
The Cardiff players had stayed neutral in the row over shirt colours and Iceland international Gunnarsson, 25, admitted they were glad the saga was over.
"Of course we are. We are in an awkward position," he said.
"But it's not down to us to make decisions on this. It's down to the owner. He's changed it now and everyone's happy.
"Coming out to a stadium where fans are lively . . . They want us to do well if we're playing in red or blue.
"It's just been down to us, we have not been performing.
"We need to take responsibility for that. We did that today. Hopefully we can build on that."
The win was Cardiff's first in the Championship for six games and lifted them one place to 11th in the table.
Cardiff are next in action at Norwich City on Saturday, where they will be wearing the red shirts that are now their away kit.