In the edit mode of your "Listenings" under the tab "Job Ad" you have the possibility to change "Colors & Language" of your job ad. You can find the corresponding settings in the footer on the right side.
Here you have in four different fields the possibility to adjust the color choice of some elements:
the background color of the Apply button & the footer,
the text color of the Apply button & the footer,
the text color of the headlines and
the background color of the entire job ad.