To set the Background color for Self service portal page, login to the application as an administrator, goto Admin- Self service portal settings .
Click on Customize Self service portal, and click on Edit.
If you have already set any background image , you need to remove it to set the new background color. For removing the existing image remove the line below,
<img src="/custom/widgets/SSP/search_widget/ssp-homepage-bg.png" class="pos-abs fw fh top0 left0">
Then in the first line next to,
<div class="ssp-requester">
insert the below,
style="background-color:#378aff"><div class="container mb30 pos-rel" style="max-width: 800px;">>
and finally the line should look like below,
<div class="ssp-requester"style="background-color:#378aff"><div class="container mb30 pos-rel" style="max-width: 800px;">>
and save. This will change the BAckground color to blue ( since i have set the font color #378aff of blue). You can set other color values as per the requirement.