back ground behind pictures

hi

how i can change backgrounds pictures behind the home page or how to remove them ??

please both possibility .
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and how i can change the text color of whole website like ( top menu,service,posts,pages) all of them looks something like dark brown even the circles .

i will attach the picture to understand it better .

https://i.imgsafe.org/4fdff39aa4.png

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as you know at the moment im working with localhost so i can′t publish my webpage but i think the picture shows everything

thank`s in advance and awaiting for your kind response !!

BR