body {
background-color: rgb(150, 150, 150) !important;
}
.container table tr td {
background-color: rgba(0, 0, 0, 0.7) !important;
}
td div, td p {
color: #F2F2F2 !important;
}
.header {
background-color: #000000 !important;
}
#pages, #upbutton, #toggle {
color: #F2F2F2 !important;
}
.pages:hover, .active, #upbutton:hover {
background-color: #505050 !important;
}
You can also use developer tools (Ctrl+Shift+I) for searching classes/id of elements. For better color you can search "html color" or use this page https://www.w3schools.com/colors/colors_picker.asp
Edited: I see what you solved issue before when I printed answer:)