How to change page color

Hi Team, 

I would like to know if I made forum for 4 pages in one forum
Can I design different colour layout or template for each different pages? 

Yes its possible. Add this CSS code to your form:

.page-section:nth-of-type(1) {

    background-color: yellow !important;

}

.page-section:nth-of-type(2) {

    background-color: green !important;

}

.page-section:nth-of-type(3) {

    background-color: blue !important;

}

How-to-Inject-Custom-CSS-Codes