I am trying to make a map of the population, at county level, to display data as proportional symbols based on the total population (to show as circles), and in the same time the symbols to have gradual colors based on the population density of the county.
The way I tried to approach this, and it did not work, was to duplicate the layer (counties) and have the top copy as proportional symbols [total_pop] (circles) with a hollow fill, and white background; the bottom copy was gradual colors [pop_sqmi]. The problem is that the background of the circles will show through the hollow symbols, thus I have black circles with white fill and background, and the second layer (underneath) is not visible.
How can I solve this problem, to make gradually colored circles [pop_sqmi], that are proportional to population number [tot_pop]?
Thank you for any insights you might have.