According to the announcement, the decision came in response to the request of the players.
Typically, the Diamondbacks' black jerseys are worn as a weekend alternate uniform but the kit for the current homestand has been tweaked, with "Arizona" replacing "D-backs" on the front of the jersey as a tribute to victims of the Yarnell fire.
A white No. 19 patch has also been placed on the jersey's left breast, in honor of the 19 men whose lives were lost while fighting the wildfire near Prescott. After the homestand, for the second half of the season, the Diamondbacks will continue to don the No. 19 patch, but it will be moved to the left sleeve of their uniforms.