uiBg
From SAP Enable Now Wiki
Scope
Web Assistant parameter, specified either in the URL or in the Web Assistant parameters in the linked application.
Purpose
Used to specify the background color or the Carousel, Bubbles (including Guided Tours), and icon backgrounds. Note that Help Tiles are displayed slightly transparent, and so appear slightly lighter than the color specified here.
Usage
Specified as:
uiBg={RR,GG,BB}
where {RR,GG,BB} are the comma-separated decimal RGB values of the required color (so “255,0,0” for red). (You can specify them as hex values [e.g. #FF0000] in the application – but obviously using a # wouldn’t work in a URL.)