When I create a line graph and set the marker_color, some of the marker lines appear the wrong color regardless of the
color I set.  The off color of the markers seems to vary depending on what the graph is doing.

Sample code to reproduce:


require 'rubygems'
require 'gruff'
g = Gruff::Line.new('120x75')
g.title = "My Graph" 
g.data("Apples", [1, 2, 3, 4, 4, 3])
g.data("Oranges", [4, 8, 7, 9, 8, 9])
g.labels = {0 => '2003', 2 => '2004', 4 => '2005'}
g.marker_color = '#FFF'
g.marker_count = 4
g.write('my_fruity_graph.png')