Hello,
The majority of the backgrounds can be adjusted in the index.php file. Just do a search for: image_title and you will see all the inherit styling. A quick search in the index.php brought up this coding block for example:
.s5_scrolltotop:hover, .button, .ourteam_roundimage_hover .ourteam_roundimage_inner, #s5_youtube:hover, #s5_pinterest:hover, #s5_fb:hover, #s5_twitter:hover, #s5_vimeo:hover, #s5_google:hover, #s5_rss:hover, li.pagenav-prev a, li.pagenav-next a, #s5_accordion_menu h3.s5_am_toggler.s5_am_open.s5_am_parent, .validate, .module_round_box-highlight2, #s5_responsive_mobile_drop_down_wrap button, #s5_responsive_mobile_drop_down_wrap .button, .pager a, button.btn, .btn, .icon_outer_wrap, .readmore a, a.readon, .ion-play-size, .circle_table_icons, #s5_is_leftarrow:hover, #s5_is_rightarrow:hover, site_logo_symbol, a.s5_ls_readmore, .jdGallery a.right:hover, .jdGallery a.left:hover, .s5_highlight1, .pager a, button.btn, .btn, .horzaccordion .image_title a.btn:hover, #myGallery a.readon:hover {background-color:#<?php echo $s5_highlightcolor2; ?> !important;}