It sounds like you're on the right track. You want to apply the addStyle to the uitable, not the uifigure:
% setup
fig = uifigure;
fig.Position = [500 500 520 200];
uit = uitable(fig);
uit.Data = rand(5);
uit.Position = [20 30 480 135];
% add some color
s1 = uistyle('BackgroundColor','r');
addStyle(uit,s1,'column',3)
s2 = uistyle('BackgroundColor','b');
addStyle(uit,s2,'cell',[1 1; 2 4; 3 5;])
