TwentyFifteen: How can it show a different color on every post page?

Question

I have made a child theme of TwentyFifteen. Am trying to set on styles.css of the child theme a specific color on every page or post.

I tried somethin like that

.post-id-no.id .hentry,.site-footer {
background-color: #RGBColor !important;
}

But I didn't see any difference, its still white. What exactly am I doing wrong?

Answer 1

The CSS code syntax is not correct. For post and page specific CSS, you need to use something like this:

/* Replace x with post/page id and post with page and vice versa*/ 
.page-id-x .hentry, 
.page-id-x .entry-footer {
   background-color: #RGBColor !important;
}