Dear awmdeals,
Thanks for contacting us and choosing our product!
About your question change color of background k2 item you can do it by following steps:
Step 1: Go to path {root}/templates/jux_ciao_local/css then open file template.css
Step 2: Go to line 5081 then change background color to other color you want
If you use joomla articles you can do it by followings steps:
Step 1: same above
Step 2: Go to line 2316 then change to color you want
Hope this help!