I know how to set a color variable like so:
mycolor=rgb(12, 120, 220)
But I would like to know how to set the background color of the graph to mycolor.
Please note I’m not talking about the graph/function itself or the grid, just the background color which currently is always white.
I’ve tried googling this specific question but haven’t found anything related to background color. It seems one can easily change the color of any component in Desmos except for the background color. 
Welcome! The background sink is actually to pull graph calculator and/or sketch states from other components. There’s not a specific parameter for the background color. It’s a bit hacky since polygons will cover the grid, but you can set a polygon with your color in a hidden graph, and use that as the background for another (or more than one) graph.
i think an easier way would be to simply say something like |x|>-1 and set the custom color property to that function: Untitled Graph | Desmos
@Daniel_Grubbs Thanks for the tip about using a polygon. Seems to work, one just needs to know the bounds of the graph being plotted before hand.
btw is there a site one can make requests about such feature being added in future versions of Desmos?
@Mike_Gleeson There’s still the issue of the inequality overlaying the graph (try it at 100% fill). I believe polygon is doing less work than an inequality which is doing evaluations over a list essentially.
@desmosnewbie You can set (and lock) the graph bounds in the wrench menu. Or you can define variables and use the bounds: sink in the CL. I updated the above example to include CL defined bounds.
Horses for courses but I think using |x|>-1 or similar is much more compact and extensible.
I was using polygon() at the beginning, but now I always use |x|>=0