Hey Rikard,
this is excellent, thank you !!
Fabienne

Hey Jordan,

i really want to get this right :
so if I understand correctly what you are writing, then : http://dubbelpunt.be/wp-admin/post.php?post=18&action=edit
is page id = 18 ?

I think I also found it on the inspector :
https://www.dropbox.com/s/q4l5fxt0oikjl9g/Schermafdruk%202017-07-22%2023.52.13.png?dl=0
here I also see page-id-18

correct ?
so if I would like to change f.ex. only the background color of this specific page, then I could do maybe :
.page-id-18 {background-color: green;} ??

tx a lot Jordan, it works perfectly !

yes, of course, here it is :
I hope you understand what I mean, I hightlighted the area where I want to diminish the height :

https://www.dropbox.com/s/t96zd7jm9fjh4a5/Schermafdruk%202017-07-13%2016.25.26.png?dl=0

no…. unfortunately not…
this is the site http://www.studiolynnpieraets.be

and this is the css-code that I have already implemented, maybe there is something wrong in here ?:

.container .main-title entry-title .breadcrumb-title{display:none;}

.container {background-color:#cac8bc;
font-family:DINBek-Regular, Helvetica, sans-serif;}

.container_wrap .footer_color {padding:0px;}

.alternate_color .breadcrumb, .alternate_color .breadcrumb a, #top .alternate_color.title_container .main-title, #top .alternate_color.title_container .main-title a {
color: #cac8bc;}

#top .av-menu-button > a .avia-menu-text {
border:0px solid #ffffff;
border-radius:0px;}

#top .av-menu-button > a:hover .avia-menu-text {
border-bottom:1px solid #ffffff;}

p {margin: 0.85em 0;
margin-left:150px;
margin-bottom:10px;}

element.style {
font-size: 13px;}

.avia_textblock {
clear: both;
line-height: 1em;
letter-spacing:1px;
margin-left:0px;}

.av-styling-no-styling .avia-image-container-inner, .av-styling-no-styling .avia_image, .av-styling-no-styling .av-image-caption-overlay {
border-radius: 0;
border: none;
margin-bottom:50px;
margin-right:50px;}

img, a img {
border:none;
padding: 0;
margin:0;
display:inline-block;
max-width:50%;
height:50%;
image-rendering: optimizeQuality;}

html, #scroll-top-link {
background-color: #cac8bc;}

#top h4 a:hover{color:#808080;}
element.style a:hover{color:#808080;}

a:hover, a:focus, a:visited {
outline: 0;
text-decoration: none;
color:#808080;}

.home .av-main-nav-wrap {
float: left;
position: relative;
display:none;}

.main_color a, .main_color .widget_first, .main_color strong, .main_color b, .main_color b a, .main_color strong a, .main_color #js_sort_items a:hover, .main_color #js_sort_items a.active_sort, .main_color .av-sort-by-term a.active_sort, .main_color .special_amp, .main_color .taglist a.activeFilter, .main_color #commentform .required, #top .main_color .av-no-color.av-icon-style-border a.av-icon-char, .html_elegant-blog #top .main_color .blog-categories a, .html_elegant-blog #top .main_color .blog-categories a:hover {color: #ffffff;}

html{font-family:DINBek-Regular,helvetica,sans-serif;}
body{font-family:DINBek-Regular,helvetica,sans-serif;}

.av-main-nav>li>a, h1 {
font-family: DINBek-Regular!important;}

a:hover, a:focus, a:visited {
outline: 0;
text-decoration: none;}

#top h1 a, #top h2 a, #top h3 a, #top h4 a, #top h5 a, #top h6 a:hover {
font-weight: inherit;
text-decoration: none;
color: #808080;}

.content .entry-content-wrapper {
padding-right: 0px;}

.container .av-content-small.units {
width: 100%;}

.av-seperator-icon{display:none;}

.page-id-38 #main .main_color, .page-id-38 #main .main_color .container {
background: white;}

.page-id-38 .header_bg, .page-id-38 .container {
background: white;}

.page-id-38 #main .main_color{background-color:white;}

.page-id-38 .logo {display: none;}

.header_color .primary-background, .header_color .primary-background a, div .header_color .button, .header_color #submit, .header_color input[type=’submit’], .header_color .small-preview:hover, .header_color .avia-menu-fx, .header_color .avia-menu-fx .avia-arrow, .header_color.iconbox_top .iconbox_icon, .header_color .iconbox_top a.iconbox_icon:hover, .header_color .avia-data-table th.avia-highlight-col, .header_color .avia-color-theme-color, .header_color .avia-color-theme-color:hover, .header_color .image-overlay .image-overlay-inside:before, .header_color .comment-count, .header_color .av_dropcap2, #top #wrap_all .header_color .av-menu-button-colored > a .avia-menu-text, .header_color .av-colored-style .av-countdown-cell-inner, .responsive #top .header_color .av-open-submenu.av-subnav-menu > li > a:hover, #top .header_color .av-open-submenu.av-subnav-menu li > ul a:hover {
background-color: #cac8bc;
color: #ffffff;
border-color: white;
letter-spacing:1px;
font-family:DINBek-Regular, helvetica, sans-serif;}

html* .page-id-38 {
background-color: #fff !important;
background: #fff !important;}

thanks,
Fab.

no, doesn’t work : also : I already tried html and it gives ALL webpages white background, I only want SECOND page = white background ;

https://www.dropbox.com/s/lzxcekrcmy4s7q3/Schermafdruk%202017-02-01%2019.01.40.png?dl=0
https://www.dropbox.com/s/rhtcn4gf41ca98t/Schermafdruk%202017-02-01%2019.03.26.png?dl=0

thanks, Fab.

on this one : ” am making following website : http://www.studiolynnpieraets.be”

no no, so above site has 4 pages. Pages 1, 3, 4 have a green background color.
Page 2 (which is called ‘projects’) must have a complete white background on the page.
so, I used:
.page-id-38 #main .main_color, .page-id-38 #main .main_color .container {
background: white;}

but under the header/navigation you will still see a small line in olive green.
Can you see it ? I want it to dissappear…
But I can not figure out if this is a border-line or another element ?

found it, of course, I need to make the categories first !! (stupid)

omg Yigit, you are speedy Gonzalez !! i just posted the question :-)

by the way, it works !! however, the header and footer still remain in the other color, how do I change these as well ?