   darkGray = d3.rgb(200, 200, 200)
   pink = "#E9CFEC"
   purple = "#8C4374"
+  # bgcolor = "black"
+  labelcolor = "black"   # "white"
+  titlecolor = "blue"    # "Wheat"
+  maincolor = "darkblue" # "Wheat"
 
   # calculate X and Y scales, using cM positions
   totalChrLength = 0;

           .attr("fill", darkGray)
           .style("pointer-events", "none")

  # maximum lod score
  maxlod = d3.max(data.peaks, (d) -> d.lod)


         .text(titletext)
         .attr("x", (left[1]+right[1])/2)
         .attr("y", top[1] - pad.top/2)
         .attr("fill", maincolor)
         .style("font-size", "18px")
    else
      probeaxes.append("text")
         .text(titletext)
         .attr("x", (left[1]+right[1])/2)
         .attr("y", top[1] - pad.top/2)
         .attr("fill", maincolor)
         .style("font-size", "18px")

  # circles at eQTL peaks
  peaks = svg.append("g").attr("id", "peaks")
